Peter Delfyett

Zierler:

This is David Zierler, oral historian for the American Institute of Physics. It is June 24, 2020. It is my great pleasure to be here with Professor Peter Delfyett. Peter, thank you so much for being with me today.

Delfyett:

Thanks, Dave. It’s a pleasure.

Zierler:

So, to start, it might be a mouthful for you, but let’s give it a shot. Would you please tell me your title and institutional affiliation?

Delfyett:

Yes. I am a professor of optics, electrical engineering, and physics. I am the University Trustee Chair professor and Pegasus professor of the University of Central Florida within CREOL, which stands for the Center for Research and Education in Optics and Lasers, within the College of Optics and Photonics. And I’m also the director of the Townes Institute at UCF within CREOL.

Zierler:

See, I knew that would be a mouthful.

Delfyett:

Yeah. [laughs] I hope I got it all.

Zierler:

So, what is your home department, if you had to choose one home department?

Delfyett:

My tenure is in the College of Optics and Photonics.

Zierler:

Okay. So, it’s a college. How many departments are in the college?

Delfyett:

One.

Zierler:

Oh, that’s it? It’s a college and a department altogether?

Delfyett:

That is correct. The reason why it was turned into a college is because CREOL, which was started as sort of a research center, funded directly by the state at UCF, was a sufficiently worldwide recognized institute for a state-of-the-art research in the area of optics and photonics. And one of the provosts changed it to be a school, and then eventually its stature was raised to that of a college.

Zierler:

I see.

Delfyett:

It has evolved over the past, let’s say, 33 years that CREOL has been in existence. Again, it started as a research center. When I joined, they didn’t have a college or a school of optics, so my tenure or primary appointment was in the Department of Electrical Engineering, and I had a joint appointment in physics. Once we became a school and had our own degrees, like a master’s and Ph.D. in optics, then our tenure lines were transferred into the school, and then we retained joint appointments in the other departments.

Zierler:

So, a more microscopic way of asking the same question in terms of how you identify yourself: if you only had to choose one area of specialty, to say, “This is really what I am,” what would you have to say?

Delfyett:

Boy, that’s hard. [laughs] So, the reason is, is that all of my degrees are, in fact, in electrical engineering. So, I’ve been trained as an electrical engineer. However, when I did my Ph.D., my primary advisor was a physicist, and I worked in his laboratories doing ultrafast nonlinear laser spectroscopy. So, if you were to sort of look at the work being done, one would say: oh, you’re a physicist.

Zierler:

Right.

Delfyett:

But when I was in the classroom, I was always trained as an electrical engineer, and then when I went to industry, I tried to build a research activity that encompassed both fundamental physics but a state-of-the-art applications. So, I tend to use applications that engineers are interested in, in terms of a driver or something that guides where I put my efforts to do research, but as far as doing the research, I always started at the bottom floor to look at the fundamental limitations.

Zierler:

Right.

Delfyett:

So, I don’t know if that really answered the question or not.

Zierler:

No. It’s — clearly, you represent the idea that the barriers between these disciplines are smaller than they seem.

Delfyett:

That’s correct. I agree wholeheartedly.

Zierler:

Alright. So, I want to start at the beginning. Normally, we talk about more current issues toward the end of the interview, but I know we have some exciting breaking news here. You were recently named as the recipient of the 2020 IEEE Photonics Society William Streifer Scientific Achievement Award. So, big congratulations for that.

Delfyett:

Thank you, sir. It’s an honor, truly.

Zierler:

Would you tell us a little bit about both what the award recognizes and what your research was that got you this recognition?

Delfyett:

Sure. The award is recognizing my efforts in semiconductor diode-based ultrafast laser science and technology. I think that’s what the actual citation says: “for pioneering contributions in ultrafast laser science using diode lasers,” etcetera. So, what the award was given for, if you read the award announcement, it’s supposed to be for work done within the past 10 years, but I’ve had an entire career starting from Bellcore, which has sort of worked in the area of ultrafast lasers — again, fundamental science and applications toward signal processing. So, in some sense, the work encompasses all of that, but specifically, I helped to spin out, or I spun out, a company called “Raydiance,” which uses short pulses of laser light to do what we call non-thermal ablation. So, non-thermal ablation is using lasers to cut and modify materials by light intensity which is so bright that the light pulse goes in, it takes the electrons which form the bonds between the atoms, and these electrons are ejected due to what we call multiphoton absorption, and then the resulting atoms which are left there have a net residual positive charge, and like charges do not like to be next to each other. So, these atoms expel, or are ablated, but the most important feature is that that entire process takes place less than — on the time scale of a picosecond, or one trillionth of a second. So, if you can get the atoms to be ablated or removed in a time scale faster than it takes for the atoms to start to vibrate, which is the heat aspect of it, you’re able to ablate and remove material without leaving a residual detrimental effect of depositing heat. So, this is why we call it “nonthermal ablation.” In many applications, when you use the laser light to cut or to remove material on the surrounding areas where the laser light has interacted, there is what we call a “heat affected zone,” where if you were to look underneath a microscope, the edges look jagged. The surfaces don’t look really clean, etcetera. But the nonthermal ablation process allows you to cut and ablate and remove material with extreme precision. And we were using these lasers for applications with Samsung for cutting the electrical vias into Gorilla glass that they use for their Samsung phones. We were using the lasers for drilling microscopic holes in direct-injected fuel injectors for very efficient type car engines, and we were also using the lasers to cut the medical stents that go inside arteries to keep them open. And so, when you’re cutting stents with non-thermal ablation, the jagged edges in the stent that would normally be there associated with the regular cutting process from a regular laser, those jagged edges are no longer there, so these jagged edges wouldn’t scratch up the insides of your arteries and veins. And so, these were some of the applications that we were aiming for when we spun the company out.

Zierler:

So, this award is really, in a sense, recognizing broad swaths of your research over the course of your career.

Delfyett:

That is correct.

Zierler:

Yeah. Okay. Wonderful. So, now let’s take it back to the beginning, even before you. Let’s start with your parents. Tell me a little bit about your parents. Where are they from?

Delfyett:

Sure. My father was born and raised in Queens, New York, Bayside, as was his father, as was my grandfather’s father, as was my grandfather’s grandfather, and my grandfather’s grandfather’s father came from the island of Hispaniola. Probably came to the U.S. — we’re not exactly sure on the date, but probably in the late 1830s, because my grandfather’s grandfather was born in 1844, and we actually have records of that. And we have a copy of the 1860 census of New York City, which shows the first male Delfyett, his wife, and the first offspring, which is my grandfather’s grandfather. So, those are the first Delfyetts in the United States. So, my mother —

Zierler:

Where does the name Delfyett trace from? Do you have any idea?

Delfyett:

Yeah. Now how about this? This is an excellent, excellent question. And as far as we can tell — again, we're not 100 percent sure, but for sure the first man, the Delfyett, came from the island of Hispaniola, which today is referred to as the Dominican Republic or Haiti. It’s one island.

Zierler:

Right.

Delfyett:

The document we have says that he left from the port of Saint Dominguez, which today is currently called Santo Domingo, but at the time, if it was called Saint Dominguez, obviously that was because the French were — there was still residual history of the French control. Now, having said that, there is a small, I guess, county or borough or something, which is on the western end of the island near the Momance River, which is near Port-au-Prince in Haiti, and that little town is called Fayette. So, we’re anticipating —

Zierler:

Of Fayette. Right.

Delfyett:

that when he came over, you know, “What’s your name?” “John.” “Where are you from?” “Del Fyette. I’m from Fyette.” Now, we don’t know if that’s true, but it’s a pretty good story.

Zierler:

Now, the first Delfyett to come to the United States from Hispaniola, pre-Civil War, what would his status have been?

Delfyett:

That’s an excellent question. Since he came from Hispaniola, which was after the Slave Revolt in the late 1700s or early 1800s, I’m assuming he obviously was a free man, and came to New York, where there wasn’t slavery. So yeah, he was a person of color: “Negro,” as it says clearly on the 1860 census, but was a free man.

Zierler:

So, your entire father’s bloodline from that point was free in the United States.

Delfyett:

Yes. Correct. And again, as you probably know, slaves were freed in 1864, so my grandfather’s grandfather was born 20 years before that.

Zierler:

Of course, “Negro” is a very problematic usage. Do you have any idea what heritage there was on your father’s side of the family from Hispaniola, besides Africa?

Delfyett:

I’ve certainly done my 23andMe genealogy. [laughs] So, I know the rainbow of stuff that’s within me.

Zierler:

Right.

Delfyett:

But certainly — I don’t know the ethnic composition of my grandfather’s grandmother. I don’t know. But I do know that my grandfather’s mother is German, for sure. So, I don’t know __if___ the first Delfyett, if he was mixed in some way, but there’s been a lot of — as I said, there’s a lot of mixture along the way. As I mentioned, my grandfather’s mother is German. So, I don’t know the ethnic composition of my grandfather’s grandmother, although on the census, it also says that she is Negro. Again, I don’t know what the mixture is, but even back then, there was a lot of mixing going on. But if you had, I guess, the concept of “one ounce of Black blood,” you were basically viewed as being colored or Negro, as it was referred to at the time.

Zierler:

And now, what about your mom? Where is your mom from?

Delfyett:

My mom is Italian, although her mother for sure is Italian, and her father is Sicilian. So, Sicily is the island in the middle of the Mediterranean, just south of Italy. But now, looking at my 23andMe genealogy, there seems to be a lot of additional ancestry which may come from the Middle East, it looks like: from north Africa, east Africa, the Middle East, etcetera. So, I think that’s where — so, my grandfather being Sicilian, I think there, perhaps in his bloodline, a lot of mixture in that respect. Certainly, I know that en route from Sicily, this would be, I guess, my maternal grandfather’s grandparents. As they left from Sicily, they stayed for some years in Tunisia in north Africa, and had vineyards, and then after that came to, I think perhaps Poughkeepsie in the state of New York.

Zierler:

And where did your parents meet?

Delfyett:

My parents met in high school, in Bayside. [laughs]

Zierler:

Well, Peter, it’s funny. I have to say, it sounds like your heritage is as diverse as your scholarly research agenda.

Delfyett:

Yeah. [laughs] Thank you very much for the diversity in scholarship, but also, the diversity in terms of ethnicity. Again, when you take a look at the 23andMe genealogy report, it looks like a little rainbow. I don’t know if you’ve had these things done, but it sort of shows the different parts of the world in different colors.

Zierler:

Right.

Delfyett:

And it shows you a percentage, and my thing looks like one of these rainbows of all sorts of things. It’s impressive—

Zierler:

A similar question, in terms of how you identify yourself as a scientist — and here, there’s a duality in terms of both how you identify yourself and how others might perceive you. But is there a particular way that you identify yourself racially, or culturally, or ethnically?

Delfyett:

Sure. I identify myself as African-American, without a doubt, because I was raised by my paternal grandparents. My grandmother and grandfather on my father’s side, along with my dad, his two brothers, and my two sisters. So, we grew up in an extended family household, and I always felt that, and was sort of taught that, if you have one ounce of Black blood, you are Black. And with a name like Delfyett, growing up in Bayside, Queens, that was a recognized family name of a family that had African-American descent. So, to try to not acknowledge that, I think, is a disservice to my family, especially if I’m carrying that name. My grandfather clearly is a man of color, and has brown skin, and you cannot deny that, even though his mother is German, and my father is fair-skinned like me. But one of his brothers is also much darker in complexion. So, we have a rainbow of complexions in the family as well.

Zierler:

What year were you born, Peter?

Delfyett:

1959.

Zierler:

1959. Okay. And did you go to a P.S. in Queens?

Delfyett:

Yes, I did! I did! I went to P.S. 31, Queens, in Bayside. Then, when my dad remarried, I went to P.S. 15 in Queens, and then I went to I.S., or Intermediate School 59, in Springfield Gardens. Then I went to Martin Van Buren in Queens. And then I went to the City College, which is there in uptown Manhattan in Harlem. Then from there, I spent a few years at the University of Rochester and then came back to the graduate center at the City University of New York and received my Ph.D. I like to tell people that I am a product of the New York City public school system, from kindergarten through Ph.D.

Zierler:

There you go. [laughs]

Delfyett:

And in some sense, it really does show the importance and value of a public school system.

Zierler:

That’s right.

Delfyett:

Because without a free public school system, it would have been very difficult for my dad to have sent my sisters and myself to a college which is a very expensive undertaking, as you can probably imagine, even back then.

Zierler:

And how diverse was your neighborhood and your school growing up?

Delfyett:

Very interesting question. In Bayside, I guess you could almost say that there was a little bit of redlining going on, so if you were to look at the ethnic makeup of Bayside, Queens, where my grandfather was born was one small section where a lot of African-Americans lived. Again, now mind you, my grandfather was born in the late 1800s, and his father and grandfather [laughs] were there before then. So, there’s nothing but fields and cows. There was literally nothing there. So, this was before the New York City public school system, literally. So, over time, people and families sort of congregated together. So, the Delfyetts were in one part of Bayside, and then when my grandfather got married, he moved — it might have been maybe two or three miles away, but as time grew, again that area within a maybe two- or three-block area was primarily of folks which were also African-American. And then all around that were folks of more European descent. Now, if you go into those areas, primarily people are of Asian descent right now, if you were to go to that area in Bayside. Now, Springfield Gardens, in the south side of Queens, my school was primarily comprised of students which were of African-American descent. Whereas at P.S. 31 in Bayside, the school was primarily children from parents which were of European descent, and there were a handful of kids which were children with parents with African-American descent.

Zierler:

Now, I’m curious. Did you start showing curiosity in science and the natural world even before you were exposed to these subjects at a high level in school?

Delfyett:

Yes, as a matter of fact, I did. And I have to attribute that to my grandfather. He would sit me on his lap, and I might have been in kindergarten or so, 1st grade. And he would open up The New York Times, and he would find articles that were related to science, and he would have me read them to him. So, this was in a way that would help me practice my reading and speaking ability. So, we’d get to tough, difficult words for me to pronounce, and he’d help me struggle to get through the words. But because he had this — I loved that experience, to be able to read these science articles, whether they were about space, or dinosaurs. I had a pretty strong interest in paleontology, because my grandfather would — you know, I would read these articles in The New York Times about dinosaurs being discovered, but then I would go to a good Episcopal church, and I was very frustrated that there was no mention of the dinosaurs in any of the things that they were teaching us. And I wanted to know: why was that? How could they leave these great creatures out of the big story? So, I was very curious, even at an extremely young age.

Zierler:

And when did you start to exhibit excellence in math and science in school?

Delfyett:

Well, I think I always did well in math and science. I can even recall, maybe in the 2nd grade — first or 2nd grade, getting my report card, getting all “excellent” in science. And I was like: oh, gee. That’s interesting. I didn’t know. And so, I was very surprised. But you know, growing up in an extended family with not just my grandparents, but my dad and his two brothers, we grew up in a household that valued a good work ethic and doing well in school. And somehow, somewhere along the line, I think it was impressed upon me to just always do well in your math and science. And my grandfather worked for Powers Chemical Company, and he basically had an 8th grade education, but this was a company that made the silver emulsions for film, etcetera. So, I think he recognized the importance, or saw how real chemical engineers could make good money, so I think he also impressed upon me to, when I went to school, do well in your math and science. So, I think that was always an underlying theme in terms of the family guidance that we got.

Zierler:

Did your high school have a good math and science department?

Delfyett:

So, in Martin Van Buren — now, Martin Van Buren was on the northeast part of Queens. That was actually a decent high school. And I, in fact, think there are some Nobel Prize winners from physics that have come from Martin Van Buren. So, it was good. I always, again, made sure I did my math and science homework first, always. Again, I didn’t mess around and not bother to do math and science. I can recall taking geometry in the 10th grade. It was like doing puzzles. These postulates — you know: prove how the triangles are similar. Those were like puzzles for me. So, I can recall actually reading the math book and trying to read ahead. I can recall — to put things in perspective, going back to elementary school, I remember getting ready to go to the — I guess it was the 2nd grade, so I’m in 1st grade. And I’m asking my oldest sister. She’s getting ready to go to the — I guess she’s going to the 4th grade, because we were each a year apart. “Donna, what’s the most important thing you need to know in math in the 2nd grade?” She says, “Well, you have to know your addition and subtraction, but they’re going to teach you how to carry.” “Oh, my gosh. What’s ‘carry’?” Oh! “That’s when you add the numbers, and it’s when it’s more than 10, you’re going to take this number and carry it over.” I still had no idea what that really meant, but when I got to 2nd grade, and the teacher started this, I says, “Oh, my God, here comes the carry part. Let me pay attention.” So, I tried to use my sisters to get knowledge in terms of what they felt was important and difficult or challenging as they went through, so when it was my turn to go through it, I could perhaps benefit from their experiences. So yeah, I always tried to pay attention in math and science.

Zierler:

When you were thinking about colleges, did you know you wanted to major in math and science from the beginning?

Delfyett:

Well, so, how about this? I was always decent in math and science, but I was good in music as well. So, I actually wanted to go to school for music. I wanted to be a drummer.

Zierler:

Oh.

Delfyett:

But you know, with a sufficient amount of family guidance, the concept is — and again, there’s nothing wrong with a music degree. However, if you spend four years and you get a music degree, in addition to being in a band and playing music, what can you do with the degree but, perhaps, teach music? And so, the concept was, you know, perhaps if I went to school for something a little bit more practical, I could still play music on the side, but have a more practical professional career, as an example. So, my grandmother was thinking that I should go into accounting, because I was good with numbers. But a lot of my friends — some of my friends were going to school for engineering, so I said, well, you know — and so, the concept was, since I’m not going to go to school for music, maybe I’ll go to school and become a studio engineer. So, I’m thinking: oh, gee. Then at least it sounds like engineering, and it still is related to music. Now, at City College, they didn’t have that kind of program, even though I think they do today, but back then, they didn’t. So, then I said: well, gee, since they don’t have an academic program for studio recording, maybe I’ll become an electrical engineer, because it’s the electrical engineers [laughs] that design the instruments for the studio engineers. So, that’s how we got to electrical engineering.

Zierler:

Did you restrict yourself to applying to schools within commuting distance?

Delfyett:

At the undergraduate level, yes, because to go away to, let’s say, a state school, or not even a private school, but even to go to a state school, the tuition would have been significant. Tuition and room and board. And since my sisters and I were each a year apart, that would have meant my dad, who was a fireman, trying to support three children in college all at the same time, paying that kind of tuition, which would have been very difficult. So, at the time when I went to the City College, my other sister went to Baruch College (for Bernard Baruch), which was the business school in New York, and the other one went to York College, all of which were open admission and basically free. I think at the time when we all went, there was a $50 matriculation or registration fee at the time, and probably by the time I ended, the fee may have gone up to $250 or something like that. That’s when they started paying a little bit of tuition, back in the late ’70s or so.

Zierler:

Peter, I’m curious. Both in high school and in college, were there any people who sort of discouraged you from pursuing a career in science as an African-American? Anybody that said, you know, “This is not for you”? Did you ever receive that kind of discouraging kind of input?

Delfyett:

I wouldn’t say that directly, no. But there were times when you could sort of see that there might have been obstacles put in place to make it more difficult. You know? So, no one has ever said to me, “Oh, you can’t do this,” because that would literally have to require a one-on-one interaction.

Zierler:

Right. The modern term is “microaggression,” right?

Delfyett:

Yes. Correct. So, I wouldn’t say that, although there are certain things you hear in conversations where things are a little sort of off a little bit, but there were certainly many instances where you could see that either people say things which were a little off, which either doubt what your capabilities are or are things which are put in place, which are hurdles which make things more difficult for you to make it through the system. So, that for sure, I’ve seen plenty of that.

Zierler:

Who were some of the professors who had a positive influence on you in college?

Delfyett:

In college, I was fortunate to have very good professors in my math and science classes. This enabled me to pay attention, which was good. However, two professors that I really, really enjoyed was Professor Vincent Del Toro, who I had in Control Theory, and he would call me “Mr. Del Fyett,” because his name was “Del Toro.” He would never say “Delfyett.” He’d say “Del Fyett.” And so, I did very well in his class, because I think early on, I really understood what he wanted from us. So, I made sure to come to his class prepared, having done the reading beforehand. And I think he recognized the effort that I put into the class. And he showed that he appreciated my effort, so that’s number one. Number two, the second guy, was a guy I had for my Physical Optics class. Now, mind you, I’m an electrical engineer, and it’s sort of a little bit of a long story, but I’ll make it short. So, I’m sitting on my bed one night, and I’m looking through the course catalog, and I’m thinking what elective courses I should take, and I see one course that says: “Introduction to Lasers and Masers,” and as I read the course description, it says, “In this course, we’ll teach you about the introduction to fiberoptic communications.” And I say to myself: holy cow, that thing is going to be the thing of the future. If I get my Ph.D. in that area, that’s going to carry me through a career. So, I said, I’m going to take this course. So I said, well, gee, what are the prerequisites? One prerequisite was electromagnetic theory, which I was taking, and the other one was physical optics. So, I said, oh, gee. That’s another elective. I have to take another science elective. Maybe I’ll take that. It was the professor in that course, Professor Robert Alfano, who ultimately wound up being my Ph.D. advisor —

Zierler:

Wow.

Delfyett:

Yes, it was a circuitous route. I was introduced to him as an undergraduate, probably as an early junior, taking his Physical Optics class. And I walked into his class, and there were, I think, four people. Physics classes were pretty small. And he says, “I know you. I know you. I know you. Who are you?” [laughs] And he looked at me, because I’m the electrical engineer. You know, not taking any physics classes.

So, I says, “Hi, I’m Pete Delfyett. I’m an EE.” — I know you. I know you. You’re all physicists. Who are you? He says, “EEs? All EEs are turkeys! What are you doing here?” So, I thought this was great, because growing up in an extended family household, my uncles, who were like big brothers, you know, they would use that term of being a “turkey” as a term of affection. So, I felt very warm and embraced by this acknowledgement that I’m a turkey. This is great! Wonderful! So, Professor Alfano was a good teacher, but he would also bring into the classroom real-world examples of what his research was doing. And I can recall one day him bringing me into the laboratory, and one of the picosecond labs was working. And the laser fired a flash of green light. He said, “Oh! Did you see that flash?” I said, “Yes!” He said, “That flash of light lasted for one trillionth of a second.” And I was like, “Wow. This is what I want to do.” So, that’s what really sort of got me hooked into the idea of wanting to do ultrafast optics. I was very much into optical signal processing at the same time as well, being an electrical engineer, because EEs do lots of communication and signal processing. But those were the two professors: Professor Vincent Del Toro and Professor Robert Alfano, that really sort of stuck with me.

Zierler:

Did you have good lab opportunities as an undergraduate?

Delfyett:

As an undergraduate, undergraduate students had to take four required laboratories in the electrical engineering part, doing circuits. I had to take some laboratories in chemistry. I had to take some laboratories in physics. These were all part of the course curricula. But the laboratories were decent. And also, as I mentioned, I took the Introduction to Lasers and Masers class, and there was also a laser lab associated with that as well. So, just having an opportunity to work in the laboratories was good. I also had a chance to do some undergraduate research with an electrical engineering professor, George Eichmann, and also with Professor Robert Alfano. Now, of course, they don’t let you drive the really big things, but just being allowed to be around other grad students and being in the environment sort of gets you acclimated, gets your hands dirty a little bit. No, you’re not doing state-of-the-art stuff. The fact that they may sit you in the corner and let you kind of play with something so you’re not going to do harm to yourself or others, it’s still a wonderful opportunity.

Zierler:

Did you have any summer internships in EE or other relevant fields?

Delfyett:

No, I did not have any specific internships where I would go to work at a company or something like that. Now, I did have part-time job work during the year and during the summer. It was at an architectural and arts supply store called Charrettes, which was on 54th Street right off of 3rd Avenue in New York City.

Zierler:

At what point did you think that you wanted to pursue a graduate degree in EE?

Delfyett:

Again, I’ll come back to this point of sitting on the bed one Friday night, looking through the course catalog and seeing fiber optics as an application of lasers, and me saying to myself: if I get a Ph.D. in this area, it’ll carry me through a career. That is probably the first time when I really started thinking about Ph.D. in the area of optics. Prior to that, I sort of already had a good feeling I wanted to go to graduate school, but the concept was: okay, if I get a bachelor’s degree in electrical engineering, I’d really thought about the possibility of maybe getting an MBA to have a business application with a technical background. I thought about maybe going to graduate school for biomedical engineering, because that was the advent of robotics and some of my friends were trying to go to medical school. But ultimately, I also thought about maybe doing a law degree, to become a patent lawyer, as an example. But once I started to learn about optics and lasers, the Ph.D. in lasers became the main focus, and that was, again, probably when I was a first-semester junior, perhaps.

Zierler:

And pursuing the Ph.D. was specifically about — did you think that you wanted to be a college professor? Was that part of the calculation as well?

Delfyett:

By the time I really started doing graduate work, again, I thought I would probably like to go to industry and be a researcher in industry. Now, being a professor always was something very intriguing, but at some point, I recognized that there was the potential of being in industry for a while, and then coming back to be a professor, because that’s what my advisor, Professor Alfano, had done. He spent some time in GTE research lab and became a professor. And so, I had always toyed around with that a little bit, but when you’re an undergraduate or getting ready to go to graduate school, being the academic is not necessarily the end-all goal at that time. You still have the options of industry or academia, and even if you’re in industry, do you take the complete technical route all the way, or do you decide to do technical route and then switch to a managerial branch at some point? These are all things that are possibilities, which you keep out there, and you make sure that as you take your steps forward, you try to take steps that continue to keep those options open. That was the main plan.

Zierler:

Right. Right. Did you end up going to Rochester immediately after your summer after you graduated?

Delfyett:

Yes. So, it turns out I graduated —

Zierler:

May ’81?

Delfyett:

It’s actually February of ’81. Four and a half years. The actual degree requirements, when I started, the program was 145 credits to graduate. Which, there’s no way to do 145 credits at three credits a class in four years. There’s just no way. I mean, do the math. It’s impossible. By the time I graduated, they’d reduced the course requirements to 136 credits. I think I graduated with 141 credits, and my degree is actually not a bachelor’s of science, but it is a bachelor’s of engineering, in electrical engineering. So, I graduated in February of ’81 and then went to Rochester that following September, let’s say. I went up in August.

Zierler:

Now, Rochester has one of the best optics programs in the country. Was that one of the things that was attracting you at that point?

Delfyett:

That is correct. And so, now I did not — at the time when I applied, I was not aware that the Institute of Optics was actually a separate degree program, because at City College, the institutes were sort of housed within a conventional college. Like, Professor Alfano’s Institute for Ultrafast Spectroscopy and Lasers, that’s housed within the College of Arts and Sciences. You know, institutes for transportation and safety in College of Engineering, that’s in the College of Engineering, so those institutes were parts of colleges. So, I applied to the College of Engineering, assuming the Institute of Optics was an institute within engineering. I was obviously a bit naïve and didn’t do my homework sufficiently good enough to know the difference. So, when I was accepted, I was accepted into the Ph.D. program in electrical engineering, and was not really aware there was a difference.

Zierler:

Right. Right. So, in terms of setting the stage for how big your world is, as a city boy your whole life…

Delfyett:

Right.

Zierler:

…had your family done vacations? Had you done any traveling, or was Rochester really as far as you had ever been since you were born?

Delfyett:

Excellent question. When my oldest sister Donna graduated from 6th grade — I guess I was graduating from 4th grade — my grandmother took my two sisters and myself, Donna, Barbara, and I, to Niagara Falls. It was the first time I was on a plane. It was my sort of first time away, although I did do like a long weekend in Vermont. My uncle, my father’s brother, owned some land in Vermont, and we did a long weekend in Vermont. So, I didn’t really have a lot of traveling, per se. Then when I was in college, my best friend, his mother is from Bermuda, so he had aunts and uncles in Bermuda. So, he said, “Hey, Pete. You know, if you can scrape some pennies together, buy a plane ticket, and we can go spend three weeks in Bermuda.” So, we did that and stayed at his relatives’, at his aunt and uncle’s house. That was really my first time really being away. I had never really done any real vacationing or going anywhere to see anything other than New York City, and that was my first time being away. And seeing the blue water and colorful birds and the great weather, when I came back from Bermuda, the first thing I did is I took out a map of the U.S., and said: where in the U.S. might it even remotely look like this? And I said: Florida. One day, I hope to be doing lasers in Florida.

Zierler:

[laughs] Mission accomplished.

Delfyett:

And at the time, there really wasn’t a real large, major laser industry in Florida at all. At best, you might have had some work going on at NASA. But by the time I got into graduate school, University of Central Florida had just started CREOL, the graduate program in optics and photonics. And I’m thinking to myself: one day, I’m going to go to Bell Labs — my goal was to go to Bell Laboratories, and after that, if I decide to do an academic position, that’s one of the places I would really want to try to go to. And miraculously so, I was able to go to Bell Communications Research in the early part of my career and actually become a faculty at University of Central Florida in CREOL. It’s amazing that those things actually happened, and I sort of planted the seeds back as an undergraduate, and actually made it happen as a professional. It’s amazing that it actually happened.

Zierler:

Were you nervous, both as a kid from New York and also as a person of color? Were you nervous going to Rochester? Did that seem like a very far away and alien kind of place?

Delfyett:

Certainly, it’s a little bit daunting, a tad bit, because you know, you get there, and the student body is somewhat homogenous. You know, there isn’t a lot of diversity amongst the student body, and certainly, no diversity amongst the faculty as well. And so, I can recall one student asking me, saying: oh, you came from CCNY. Is that a community college? So, right away, you get the feedback that either they’re questioning your ability or whatever it is, because how can you get into a Ph.D. program with an associate’s degree from a community college. Right? That doesn’t work. So, then why are people even asking you these questions? Well, you experience things like this. Right?

Zierler:

Did you feel well prepared relative to your cohort of students when you got to Rochester?

Delfyett:

Certainly there was a difference in the way that subject matter was being taught. You know, at the City College, at CCNY, I think they recognized that most students which are there, they’re being trained to be engineers in the field. Right? Whereas — so, working engineers, so things are very practical. I think people are teaching classes with an idea that we’re teaching you to be extremely practical, whereas the coursework at Rochester had a little bit more of an emphasis on theoretical aspects. Definitely different in that respect. However, I thought that my preparation was quite good, and so I did well in my coursework at Rochester. I passed the Ph.D. exam. That portion that had to do with image processing, which was going to be my expertise, I scored 100 percent on this section of the qualifier. I made it to candidacy, etcetera. So, in that respect, I was well prepared.

But nonetheless, for sure, I would not say that I felt completely embraced by my classmates. And again, it might not have been anything done specifically, but I can recall another particular instance. You know, I’m there in the engineering building, Hopeman Hall, one evening, and I’m walking around looking for some chalk, because I want to do some calculations on the blackboard. And I go into one of the classrooms, where I’m walking past, and say there’ll be chalk in this room. And I open the door. This is about 8:30 at night, and there is everyone — or a grouping, a subset of students from my solid state physics class, in there all doing the homework together. And I open the door and look in, and everyone sort of turns their head and looks at me, and they all sort of look shocked. And I sort of look like — oh, clearly I wasn’t invited to the homework party. [laughs] So, I said, “Oops. I was just looking for some chalk. Sorry about that,” and closed the door and went away. But it was things like that, little things, which sort of was a reminder that you may not have been completely embraced. Again, I don’t want to necessarily say that was done on purpose or whatever, but things like that sort of — you just sort of remember the feeling that kind of runs through you when you open the door and everyone looks a little shocked. I don’t know why they looked shocked.

Zierler:

Yeah.

Delfyett:

But it sort of caught me a little off-guard.

Zierler:

So, at what point did you want to cut off at the master’s degree and not pursue the doctorate at Rochester?

Delfyett:

After two years, I got my master’s degree, and I advanced to candidacy, but I really wanted to do optics. And as you know —

Zierler:

When did that happen? At what point did you decide optics is where you want to be?

Delfyett:

It was before I went to graduate school. Again, I wanted — I applied to the Department of Electrical Engineering/Institute of Optics. And when I wrote my statement of objectives, I clearly said I wanted to do work with ultrafast lasers or optical image processing. Here are new activities with X-ray lasers, potential at the laboratory for laser energetics. It was clear that I wanted to do optics. Not only that, but when I got there, they said: okay, let’s decide what courses you want to take. I said: yeah, great! I want to take Optics I, Optics II, Optics III, Optics IV, da, da, da. And they said: gee, that’s great, but since you’re a EE, we think you need to take the EE classes so you can pass the Ph.D. exam in EE. So, I said: oh, okay. I guess that sounds reasonable. But then as you know, in graduate school, eventually you need to be supported off of a contract or grant that someone is doing research. Right? So, there weren’t any faculty doing research in optics in EE. There were faculty doing research in the area of superconductivity, but now, they were faculty over in the Institute of Optics that were doing research. But I can recall my advisor said, you know: we’re supporting you off of departmental funds here. Do not go over to the institute looking for support from them. So, I said: oh, gee, that’s not a good thing. [laughs] You know, a little worried. But nonetheless, I went over there anyway to probe around, to look. And by this time, I’m getting ready to start my third year. And some of them said, look, you know — and at that point, it really became clear that graduate research is done a little bit sort of like a business. You have to run it a little bit like a business. And so, one of the faculty said: look, we’ve got our own students that we have to support. We’ve got our own optics students here that are coming in looking to work with faculty. We have to make sure these people are aligned with faculty. So, those faculty are going to use their research dollars to support their students, and those faculty are going to cover those students before we start looking for students outside the department. So, it became clear that there are, or were, walls between the departments, in terms of it not being easy for a student in one college or department to go work for another student in another department. Right? So, being that it became — so, once faculty said he would be willing to take me on working in detector work, detector arrays — but then, you know, I wanted to do lasers instead of detectors, and then also hearing my other advisor in EE saying, you know: do not go behind my back and go over into the institute and look for funding. I said: gee, [laughs] this is not looking like a good path. And had I stayed at Rochester in EE, I would have been guided down the path of doing research in superconductivity, which is not really what I wanted to do.

Zierler:

Yeah.

Delfyett:

So now, with that in mind, I think I had come home — I was talking to one of my friends who was still at graduate school back at City College, and he said: hey, Pete, remember your old professor, Professor Alfano? They just made him a joint professor in electrical engineering. Because when I was back at City College, I could recall asking him about being a graduate student with him. He said: well, gee, you’re an electrical engineering student. I’m a physics professor. I have students that get Ph.D.’s in physics. In order for me to grant the Ph.D. in physics for you, you would have to take the Ph.D. qualifier, and you’d have to have all of that background work done. So, that is sort of not a good path. Now, once they made him a joint faculty in electrical engineering, that meant I could potentially come back to City College, still be a EE, take all of the coursework — which was familiar to me — in electrical engineering, but have Professor Alfano as my advisor, even though he was a physics professor. So, I ultimately came back to New York. I remember one Christmas I went to see him to ask him about the possibilities of coming into his group. And to make a long story short, he invited me to one of his group meetings. I showed that I really knew what I was doing. I was more vocal and active in his group meeting than his graduate students. He was so impressed. He took me down to his office. He pulled a research proposal out of his drawer, and he said: this is the new work we’re going to get funding for starting in the summer. This is what you’d be doing. And he gave me a copy of the proposal. He said: there is a book out there. Buy this book. Read this book cover to cover. And that’s how it started. So, that was all in my third year of being at Rochester. I moved back to New York that May and started working with him in his group that June.

Zierler:

It was probably good to be back home after your sojourn.

Delfyett:

Yeah, it was nice being back home. New York is always good. And being back home, the other advantage was I could then live with my grandparents, so that I didn’t have to pay the significant money that there is for rent in New York City. That was a very big bonus. Even though I was getting a graduate stipend, I could use some of that money to save, buy myself a little car to get around in, etcetera, etcetera.

Zierler:

Did you end up doing a thesis at Rochester, or it was just a matter of completing the coursework for the M.S.?

Delfyett:

So, I did coursework, and I did what was called a master’s project. I actually created a microwave hologram, a little experiment, and I recorded the diffraction pattern in the far field and took this recorded diffraction pattern and computed the inverse Fourier transform to compute an image of the object. And I was utilizing the faculty from the Institute of Optics, a professor Brian Thompson, who was the director of the institute, who was an expert in holography, as one of my advisors for my master’s project. So, I wouldn’t necessarily say it was a master’s thesis, but you definitely had to do a master’s project which was experimental in nature but wasn’t necessarily written up in terms of the black binder books that they have the theses in. But it was more than just checking the boxes for just completing coursework.

Zierler:

Now, the M.Phil. that you got in 1987, was that incidental on the way to the doctorate, or that was a separate program?

Delfyett:

No, that — basically, the M.Phil. degree, in many institutions — and I say this with all the love in my heart — but it is literally an acknowledgement of you having completed all of the coursework for Ph.D. except for the dissertation. So, some people refer to it as an ADD degree. “ADD” stands for “all but the dissertation,” as an example. That is like, in Monopoly, passing Go and collecting your $200.

Zierler:

Now, how well integrated was your research assistantship with your overall graduate study?

Delfyett:

Highly integrated. I mean, for sure, as a graduate student, part of my assistantship, I was getting support for being a lab TA. Fine. We all have to do the TA work. It’s part of your training. But when I finished doing my coursework and the TA’ing and all of that business, the research that I was doing for my support, which was supported by the Air Force Office of Scientific Research, literally doing four-wave mixing and phase conjugation for activities in Raman spectroscopy and condensed matter. That research proposal is exactly what I was doing for my thesis. So, it wasn’t like I was doing experiments to support myself, but I was doing a research topic on something a little bit different. That overlap was 110 percent.

Zierler:

And how did you go about developing your dissertation topic?

Delfyett:

The dissertation topic was one of the proposed concepts in this proposal. The key trick was: I had to make it work. And on the surface, if you took a look at the tool that I had, I had a laser pulse, which was about 30 picoseconds in duration, and the concept was to use the pump-probe technique, which was like an optical sampling technique, to measure the lifetime of the vibrational entities in condensed matter — phonons, if you will. Now, these things vibrate and last for time durations of a few picoseconds, so it’s very difficult to measure 10 picosecond temporal events with a 30-picosecond laser pulse. If your yardstick is 1 meter with no gradations on it, how do you measure something less than a yardstick? Right? You can’t. That was the difficulty. I can recall saying to my advisor, “Gee, Professor Alfano. Doing the pump probe measurements with this 30-picosecond laser pulse, we’ll never be able to time resolve the phonons. And his response was, “I don’t care. This is your job. Get back in the lab and make it happen.” [laughs] And so, fortunately, there was a lot of serendipity that happened, fortunately, during the process. And I, in fact, invented a new technique that even though the laser had a 30-picosecond laser pulse, I could measure time events that had a resolution down to 2 picoseconds. That was literally the breakthrough. That was sort of the novel trick breakthrough, new physics, on how we could actually do that. Then, I used the tool to study the vibrational dynamics of phonons in calcite and vibrational dynamics of phonons in lithium niobate.

Zierler:

Now, when you say this is a breakthrough, what is now possible as a result of what you figured out that was not possible previously?

Delfyett:

What we figured out was that when you take a laser pulse of light, and you focus it into any sort of matter — solid, liquid, or gas — if the pulse is short enough, and if the intensity is bright enough, that green laser pulse converts to white light. We call this “supercontinuum.” My advisor is the one who discovered this effect back in the early ’70s. Now, what we did not know was that if you took that 30-picosecond flash of white light and passed it through a filter, where that filter would only pass a limited range of colors, the resultant pulse that made it through that filter was dramatically shorter in time. So, that 30-picosecond flash of white light, when you passed it through a filter that passed a small range of, let’s say, yellow colors, that yellow flash of light was 2 picoseconds in duration. That was the breakthrough that no one knew could happen.

And it was because of that short event in the white light that enabled me to recognize that instead of using the pump-probe technique or optical sampling technique, I could use a streaked camera and monitor the shape of the Raman signal that was coming out of the sample, and the shape of that signal would have a decay tail that would have the information of the phonon lifetime. So, this became a single-shot technique that would allow us to measure the entire vibrational signature of an unknown sample and measure the phonon lifetimes of each one of the vibrational modes in a single shot. And so, I can recall the folks at Lawrence Livermore National Labs was very interested in this technique, because they do lots of experiments where they’re only allowed one shot. [laughs] As you can imagine [break in audio] a lot of those, they were very interested in this particular technique.

Zierler:

Peter, I’m curious. Obviously, you’re inhabiting a world of experimentation. Right?

Delfyett:

Yes. Yeah.

Zierler:

Can you give a sense of — what are some of the theories in physics and electrical engineering that are important for your work that are informing how you’re setting about your experimentations and your awareness of how you can push theory forward as a result of doing these experiments and achieving these breakthroughs?

Delfyett:

Sure. Absolutely. So, I will first admit to say that I am a — what I call “application pull” type research, as opposed to a technology push kind of guy. That means I look at applications and I say, “Where is the bottleneck?” And if I can solve your bottleneck, then people are going to want my solution, as opposed to me being in the lab trying to figure out: can I do something novel? And then when I make something novel, I come out of the lab and say: look, I made a widget. Let me try and shove it down someone’s throat. That’s not my style. So, what I do in terms of doing research, if I can find where there’s a bottleneck, I go into the laboratory, and I study the physics associated for what those bottleneck principles are. And if I see any effects which are sort of novel or different, then these new or novel effects that we see then require us to modify our theories which have come up with new models to explain these effects. That’s how we push the theory. We don’t necessarily think: here’s the theory. Let’s push the theory. No. We do experiments, and we say: gee, those are interesting effects which don’t adhere to the current theory. How do we take the current theory and modify it to then model those effects? If we then come up with a theory that models those effects, we say: aha. Not only does that theory model that effect, but we only know that theory is useful if it has a predictive behavior, meaning: with that new theory, does it predict something else that we have yet to observe, and if so, what might that prediction be? Oh, okay. Let’s see if we can look for that.

And if we can see that other effect that this new model has predicted, then we know our model is correct, and we have really done a good job in terms of pushing the theory forward. Now, once I have seen new physical phenomena, and we’ve come up with new models that are predictive that can not only explain what we saw but predict new things, what we then do is we take these new phenomena and behavior and we go into the clean room, and we try and fabricate new devices that exploit these new phenomena, so these new devices will have new functionality: new switching speeds, new modulation capabilities, new efficient ways to produce light. So now, once I have a new device that is exploiting some new phenomena that we discovered, some new physics, this new device has some interesting functionalities. These new functionalities can go in and solve a problem which has been a bottleneck. Right? So again, instead of me doing physics to see an effect, to make a device that says, “This has a new functionality. Someone please buy it,” again, I look for the bottleneck. I study the physics of the bottleneck, so that when I do understand new theories and get new phenomena when I make a device, that new device will go and solve the problem of that bottleneck in the system.

Zierler:

And this has been your approach over the course of your career. This is how you’ve done your work.

Delfyett:

So, how about this? That style of research I learned during my time at Bell Communications Research. I had a beautiful diagram. It was like the triangle. I’ll call it the “golden triangle.” One thing was “materials research,” and it had arrows going both ways to devices, meaning that when you got in — you know, their fundamental science goes to devices. And then there was another spot up here which was “systems applications.” So, they had double arrows going between each of the three little balls of that thing, even though you like to say materials science and physics, devices, to systems, anytime you learn something in any area, that information you learn can be fed back to the device area or the physics area to help refine their activities as well. So, I liked that philosophy. I thought it was great. It really shows you how fundamental science can evolve to more applied aspects of science, like devices and its systems, and I wanted to keep that kind of philosophy as a part of my own research activities.

Zierler:

So, how did the opportunity at Bell come about for you?

Delfyett:

How did that come about? That’s great. Several of my friends or colleagues or students that I knew from Rochester had graduated and gone to work for Bell Laboratories. So, I was several years behind them, so I sort of knew some people there as members of the technical staff doing ultrafast optics. My advisor, Professor Alfano, was also world-renowned in ultrafast optics, and so I wanted to go to this particular place. So, I can recall one time we had a guest speaker, Jack Tomlinson, come to City College to talk about new work in optical solitons. And just because I was very much into nonlinear optics, and I studied hard, I was literally sitting in the back of the room on top of the radiator. So, I was a little bit elevated from the rest of the seats, but way in the back of the room. And I was just like grooving on this guy’s presentation. I was with it all the way. So ultimately, after the talk is over, he comes by and does the lab tours, and he’s going to see my poster. I really gave him the sales pitch for why this stuff is good. I can really sell work good. People have told me I can sell refrigerators to Eskimos. But anyway, after I was done, he was so impressed. I said, “Well, if you think that was so impressive, why don’t you just hire me?” [laughs] So, I planted a seed. Ultimately, when it was time for me to graduate, I was applying to Chuck Shank’s lab at Bell Laboratories and to the Ultrafast Optics group at Bell Communications Research. I mean, they used to be the same laboratory, but they were split apart when AT&T was sued. So, Bell Labs and Bellcore were basically the same places, but they wound up being in two separate buildings in the same town. So, I was applying, and that time — this was probably the late ’80s — there were sort of hiring freezes everywhere, but I was getting opportunities to come in and interview. And I had an interview at Bell Laboratories, and they were going to make an offer to me as a postdoc. But from Bellcore, I was hearing that there were hiring freezes, etcetera, etcetera. So I said: well, gee. I’d be more than happy still to come in and give a seminar. They said: great. Wonderful. We’ll do that. So, again, I had interviewed at Bell Labs, and then the day I go to give the seminar at Bellcore, I show up in Jack Tomlinson’s office — that was the guy that I knew — and he picks up the phone, and he’s calling the people to round up other folks that I’ll visit. And he says, “Oh, the interview candidate is here.” So I’m thinking to myself, “No one told me this was an interview.” [laughs] Had I known this was an interview, I would have worn my black suit, but not my gray suit. So nonetheless, I go and give my seminar, and again, I have a very excitable, passionate, animated personality when I talk, when I’m very excited about my research. When I was done giving the talk and was walking out of the room, the assistant or area vice president came up to me and said, “We know you’re interviewing at Bell Labs. Did you sign any paperwork?” I said, “No.” He said, “Good, because we’re going to make you an offer.”

Zierler:

Wow.

Delfyett:

Wow! I had no idea this was even an interview, and after my seminar, I knew an offer would be coming. More importantly, that offer came as a member of the technical staff, as opposed to a postdoctoral research associate. And so, I obviously took the position at Bellcore.

Zierler:

And was Bell Labs — was it legendary in your mind? Were you aware of its history in basic science research, and was this the place that you really wanted to be?

Delfyett:

Oh, yeah. That was the Mecca. I mean, this was where all the great advances in ultrafast optics were happening at Bell Laboratories. Now, having said that, I guess it might have been in 1984 where Judge Green had this thing called the modified final judgment, which basically took AT&T and split it in half, where AT&T became the company that did long distance communications, and the rest of the country, the other half of AT&T would be split up and be assigned to seven different regional “Baby Bells,” which the research arm, they called “Bell Communications Research,” and the Baby Bells were like, US West, NYNEX, Bell Atlantic, Pacific Telesis, BellSouth, Southwest Bell and Ameritech — those were the seven regional Baby Bells, and Bellcore was the research arm that would do research for local area communications for the Baby Bells, where the other half of Bell Labs would then do the research for AT&T. So, a lot of the people that were doing ultrafast optics, or some of those people, wound up going to Bell Communications as opposed to staying at Bell Laboratories.

So, at the time, Bell Labs still had that tremendous history of Nobel Prize winners, etcetera, and Bellcore was sort of the newer kids on the block. Although, all of the people there were Bell Labs people. So, in some sense, it was just a change of the name: same people, different building. And so, I chose Bellcore simply because I had an opportunity to sort of run my own research group, which then was in the area of ultrafast laser diodes, and that’s where I started that whole area for my career. Because as a graduate student, I was doing phonon physics with these huge, cannon-type lasers that put out fractions of a joule type energy, and semiconductor lasers are these tiny, tiny devices — picojoule devices. And I said, “I would be happy to do the semiconductor stuff, but I never did this. Why do you think I’m good for this?” So they said, “Well, we think that someone with your expertise, someone that knows ultrafast really well, and someone that knows nonlinear optics really well — those are really the fundamental things of knowledge that we think someone needs to have to be successful in the area. And you have that, and that’s why we think you can be successful in this area.”

Zierler:

What were your impressions of Bellcore in your first days and weeks there?

Delfyett:

Certainly, it is daunting. There’s nothing — how else can you say it? Everybody. Everybody who’s there is sort of world renown in their own area. The senior scientists, and even the junior scientists — all of the junior scientists who have been there for one or two years have managed to sort of become internationally recognized. And all of them are coming from top-notch schools: Berkeley, Stanford, Harvard, MIT, all of the big schools. You know, they are there. And for sure, I’m coming from City College, a lesser-known sort of school, although my advisor was well-recognized in the area. So, it was daunting to say the least, but I had lots of good people around me, good mentors, and again, serendipity happens along the way. It acts just as certain types of materials and devices and technologies and capabilities, and after about a year and a half at Bellcore, I had broken the world’s record for the shortest, most intense pulse from a mode locked semiconductor. So, within 18 months, I had immediately become the new kid on the block that was the leader of the field, so to speak.

Zierler:

Was the environment one in which you were fully able to pursue your own research agenda, or were you expected to take on projects that were of broader interest to Bellcore?

Delfyett:

I think the key feature is, when I went to Bellcore, they had two general areas that I could potentially go in. One was kind of Fourier-based optical signal processing, and the other one was to develop compact source of short pulses with high power, with applications in applied photonic networks. And so, that was the area that I chose. Generally, they have the concept that you work on your main meat and potatoes. They’re not going to necessarily tell you how to do it or what to do, but as long as you’re making progress and trying to advance the state of the art in pulse production, in power production for nonlinear optical photonic switching, you’re good to go. They also would like you to have side projects that might be higher risk long term, projects which might be sort of short-term low-hanging fruit, etcetera. So, you can’t necessarily just walk into the lab and say: I want to do apples, where apples have nothing to do with what Bellcore wants you to do. So, in that respect, Bellcore was a little bit more applied than Bell Labs, because there was a direction that they wanted my research to go in. So, in that respect, there was not complete, unbridled freedom, but definitely an area or a vector, a sector, that they wanted me to go after.

Zierler:

What was the research culture like there? Were you able to collaborate with people in different groups? Were you able to meet people in cafeterias and bounce ideas off of them? What was the culture like at Bellcore?

Delfyett:

Personally, I actually think — and again, it’s hard to know, because I haven’t experienced the Bell Labs culture — but the Bellcore culture was extremely collaborative. Really. And I think they really stressed that, because I think perhaps that Bell Labs, while there might have been a bit of a collaborative atmosphere, but there might have been a sense of a little bit more competition amongst the members of the technical staff, and I think that was something that they wanted to change at Bellcore. Because if you could show that you were collaborating in a meaningful way at Bellcore, they gave you lots of brownie points for that when it came time for your annual review. So, that turned out to be great. Now, with respect to sitting around the lunch table, we all did that at Bellcore for sure. However, the difference between sitting around the lunch table at graduate school versus sitting around the lunch table at Bellcore: at graduate school, you could just spit out a half-baked idea that was just completely — not even baked, [laughs] you know, and just kind of bounce it around and enjoy the conversation. At Bellcore, your idea had to be more firmly baked to share at the lunch table. It had to be more firmly baked. I think that’s a good way to put it. [laughs]

Zierler:

Peter, how well integrated did you feel you were with your academic colleagues when you were at Bellcore? Were you collaborating with the academic world? Were you presenting papers at conferences, that kind of thing?

Delfyett:

Oh, yeah. At Bellcore, this is a research laboratory. You are expected to be the leader of your field. You are expected to go to three conferences a year. You are expected to publish papers, give conferences, collaborate with your colleagues. You are expected to be the leader of your field. If you want to do well at Bellcore — and again, I was in the applied research lab as opposed to one of the more developmental groups, so it was sort of the “researchiest” part of Bellcore. So, you are expected to be a scientist and be visible on an international stage.

Zierler:

What do you see as your primary accomplishments at Bellcore?

Delfyett:

At Bellcore, my primary accomplishments were several. One was, again, the development of the world’s fastest, most powerful semiconductor laser. I broke that record, I think, three times when I was there. Number two was using this laser for an application of what we call optical clock distribution, where we use the light, and there was so much light power coming from this, we could split the light using fiber connectors and fan the light out to literally over 1,000 different printed circuit boards, and recover a clocking signal on these boards, which had applications in supercomputers. Basically, in a supercomputer, these things are huge, and all of the electronic boards and circuits inside are going to be clocked in timing with the master clock signal. And if you’re trying to have everything be synchronous, and you’re getting computation from one side of the supercomputer, being transferred over to another side of the supercomputer, and having the timing signals or clocking signals being out of time, it tends to slow the computer down. More importantly, if you have a master clock and you need to distribute it to these different boards, this master clock signal has lots of bandwidth, and the clock’s signal gets distorted by the time it gets to the printed circuit board, also reducing the accuracy of the timing. So, we showed we could avoid all of this distortion by using an optical clock signal and distributing it inside the supercomputer. That result made it into The New York Times, the Wall Street Journal, Washington Post, Chicago Tribune, and it was highlighted as one of the top most important advances in optical interconnects of the ’90s.

Zierler:

What do you think made it so newsworthy?

Delfyett:

Because we solved the clock distribution problem. Everyone was trying to figure out how to do clocking with electronic signals. That was one, which they couldn’t do. And basically, people had thought of the potential of maybe using light, because you could pipe the light around with fibers, but no one could make a laser which had a short enough pulse with enough power that the stuff could ever be done. And so, it was my solution to solving that laser problem, which then this masterful, world’s most powerful, shortest-pulse laser was exactly what was needed to solve that clock distribution problem. So, it wound up — the solution to the laser, the result of the laser, wound up being a perfect solution for the clock problem.

Zierler:

To what extent to you attribute the quality of the instrumentation as a source for your success at Bellcore?

Delfyett:

My success at Bellcore — I think, again, it’s very much like, as one of the high-level managers, Paul Liao, had said: Bellcore is like an orchestra, and you yourself are literally the conductor. And if you’re able to collaborate properly, then you can make the orchestra make beautiful music. And if you’re not collaborating properly, it may just sound like you’re making a lot of noise. [laughs] You’re not in tune with the orchestra. You’re not in time. So, having world-class scientists to collaborate with, where they had world-class equipment, and I was able to have high-quality equipment, really made it possible to be successful. This is true.

Zierler:

So, it sounds like it’s the people at least as much as the instrumentation.

Delfyett:

Oh, probably the people are maybe even more so. It’s always about the people. Even if you don’t have the best facilities, your own creativity and ingenuity in your collaborators can make great things happen. Because remember, many times when you are on the forefront of doing science, the instrumentation that you would like to have doesn’t exist, because you’re pushing the forefront. So, you have to make this stuff up — making it up from scotch tape, toothpicks, a little bit of spit, some thread, whatever it is, to make it happen. And clearly, scotch tape, toothpicks, spit, and thread are not necessarily the world’s best instruments. However, if that’s what’s needed to make things go, then there you have it. That’s exactly correct.

Zierler:

In your experience, when you were there, would you say Bellcore was a good place for people of color?

Delfyett:

Yes, I think Bellcore was a good place for people of color. I think in general, academics or research generally subscribed to the notion that — and, at least, this is sort of my belief and hope — is that if you’re able to contribute to the knowledge base of science at a world-class level, if you’re really able to contribute at that high level, it doesn’t matter what your ethnic background is. You’re really contributing, and other people in science can recognize that contribution. Now, I know that’s a blanket statement, and I’m sure that there are exceptions to that. Other people may have, in fact, experienced exceptions to that—

Zierler:

Of course. I’m only asking your perspective on that.

Delfyett:

Right. Myself included, you know, you can hear things at cocktail parties and dinner parties where things sound a little off, and people may not necessarily mean to say anything in a derogatory way. But one particular case I can recall at one particular dinner party, an extremely world-renowned scientist said to me, he said: you know, when you first came here, I said to myself, who the hell let this kid in the door? But now that I’ve seen what you’re able to do, man, you’re really okay! And he really meant it as a real compliment, but I felt — but I can recall feeling that initial feeling of how your stomach feels and how your face gets flushed when you feel a little off — I felt a little hurt that he was sort of judging me, because — why? Because I’m coming from City College? I have no idea. But you know, the concept was with, you know, “Who let this kid in the door?” But, the fact that he ultimately found out that I was okay, you know, in his mind, it’s okay. But I originally felt a little bad at the time. But I look back, and it’s okay. I still actually keep in contact with this person over LinkedIn, so it’s okay.

Zierler:

He certainly didn’t mean any harm by it, it sounds like.

Delfyett:

Right, exactly. Exactly. As a matter of fact, he said some very nice words when he acknowledged my Bill Streifer award.

Zierler:

By 1993, I’m curious if you’re starting to think about your next opportunity amid what’s going on with the breakup of Bell Labs, if that’s a factor in your decision making.

Delfyett:

What was my decision-making concept to come to academia in ’93?

Zierler:

Well, I’m curious if by the early, mid-’90s, as it probably became apparent that where Bell Labs was headed, in terms of the breakup, that that might have been an opportune time for you to start thinking about your next opportunity.

Delfyett:

That is exactly correct. That is exactly correct. How about this? I bought my house in New Jersey. I think I had closed on August 30 of 1991. We had a meeting September 8, one week later, that said Bellcore was no longer going to support materials and device research. And so literally, I had not yet paid my first month’s mortgage and weas hearing that the role that Bellcore played, or the Bellcore that I knew, the vision that I was in that did fundamental hardware research, was going to be eliminated. That had become apparent. And so, between ’91 and ’93, a lot of the senior management you started seeing taking positions elsewhere. And so you’re thinking: gee, if the upper level management is starting to leave, people which you thought would be lifers — you know, gee, maybe they know something [laughs] I don’t know. So, then it became apparent that my group was disbanded, and I was put into another group that was tasked to do what we call “disaster recovery.” So, for example, when they had a van inside the bottom of the World Trade Center explode — this was back in the early ’90s — you know, the disaster recovery team would go in there and sort of measure the telephone switching equipment that would have been contaminated from smoke and particulates, and they would try and get a feel for whether the equipment is salvageable or not. That was one of the roles that disaster recovery group would do. And that wasn’t the only thing they did, but they would try to come up with research tools and things that would help facilitate the improved performances of central office switching, etcetera, etcetera. And I was tasked to try and come up with optical technologies that would measure particulates in the air, as an example.

Zierler:

Did you start to put out feelers among your colleagues for academic opportunities, or did Central Florida recruit you straight off the bat?

Delfyett:

Right. So, as I think the decision that made me start to look was — I went out to Sheboygan, Wisconsin, and Appleton, Wisconsin, and we went to a central office switch. And I went up to the sixth floor, the rooftop of the central office switch. And I’m physically literally inside the HVA system, where they have this six-foot fan, which is rotating, sucking the air in from the outside weather. Mind you, this is February in Wisconsin, where it’s in the teens or the 20s at 2 in the afternoon, the hottest it’s going to get. [laughs] And I have this particle detector measuring the dust particles coming by me. And the wind is zipping by me from this six-foot fan, and I could feel the water in the eyes build up from the air blowing, coming down, and I’m thinking: you know, you probably don’t need a Ph.D. to do this work. So, when I got home from that trip, I had basically said to myself: it’s time for me to start looking.

Zierler:

And you’re thinking back to Bermuda, and you’re thinking: lasers in Florida. Remember, lasers in Florida.

Delfyett:

And for sure, I knew that CREOL was probably five or six years old, and I started applying around to different places of where I thought might be nice places to go. And for sure, UCF was one of them.

Zierler:

Now, can you give me a little institutional history on the origins of CREOL? I know it’s before your time, but you were probably aware of it, how it started.

Delfyett:

Sure. Absolutely. For sure. So, what happened was there was a growing electro-optics community in Orlando. Litton Lasers was one. They were making electro-optic and laser technology for Lockheed Corporation, and maybe a little work with NASA. And I think the people that were running these companies went to these legislative bodies within the state of Florida and said: hey, guys. We know that you want to diversify the tax base in central Florida. We know you want to diversify and increase the different economic sectors within central Florida. We think one way to do that is the high-tech sector, and not only that, but we have a growing electro-optics and laser high-tech sector that is here already. One way to grow that sector is to create a research center of excellence, and let’s house it at University of Central Florida, right smack in the middle of Orange County or Orlando, where the goal of this center would be to work with local industry and to train people, scientists that would go work in these industries. And that’s how we would grow that high-tech sector, by training people to go work in the companies and by creating new technologies and inventions that we would either transfer to these industries or to spin out new companies that would be in the central Florida area.

Zierler:

So, CREOL really had a regional perspective to it.

Delfyett:

Yes. Yes, yes. That’s how we were able to convince the state legislative bodies to put up taxpayer money to do that. That is exactly how it happened. And so we started where we then — CREOL then hired maybe 15 or 16 faculty. There were maybe three or four hired at first, but then it grew to around 15 by the time I was there.

Zierler:

So, you were what, like a second-wave hire?

Delfyett:

I would basically be — yeah, considered that second wave, about five years in. Yeah.

Zierler:

How well was the program developed by the time you arrived?

Delfyett:

It was certainly off the ground, still quite young. At that point, CREOL was still called The Center for Research in Electro-Optics and Lasers, before we even changed the name to Center for Research and Education in Optics and Lasers. That’s a whole ’nother story in itself. But by the time I got there, there was a well-defined course curriculum, even though all of the optics courses were either listed in the physics department or in the electrical engineering department, because we didn’t have our own academic degree program at the time. But we had our own effective sort of selection of courses, if you wanted to graduate with a EE degree or a physics degree from CREOL faculty. That is correct. So, the academic part was pretty much developed.

Zierler:

By you joining CREOL, did you see this as an opportunity to continue on with the research you had done in Bell Labs, or was this an opportunity to move into new areas?

Delfyett:

Basically both.

Zierler:

Yeah.

Delfyett:

Right? And so, when I was at Bellcore, I could have had a zillion ideas, but because I only have two hands, I can only work on one or two or three projects at a time. I’ve got limited bandwidth, being a single person. As a faculty, with grad students, I can have many grad students, and then my vision of having a zillion ideas — where these zillion ideas may actually fit in together like pieces of a puzzle for a large, grand vision — I can then have each of the different graduate students working on a different piece of the puzzle. And it enables me to diversify my research activities. And again, by collaborating with other faculty at CREOL, with completely different areas of expertise, gives me an opportunity to branch out into new areas.

Zierler:

Did you take graduate students on right from the beginning?

Delfyett:

Oh, yeah. For sure. Walk in, part of my start up package. I was fortunate enough to be able to buy my research equipment from Bellcore so I could build my labs up right away. I had one grad student waiting for me when I showed up, and I worked with him, literally just sort of rebuilding up the laser systems that I had back at Bellcore, getting them built on the table and starting an experiment to collaborate with one of the faculty there at CREOL, and write grants, and start to prepare for classes. So, I went in and just hit the ground running, building the lab, writing grants, preparing notes for classes.

Zierler:

And in terms of building the lab, was the funding appropriate for what you were looking to accomplish from the beginning?

Delfyett:

Yes, Bellcore was basically sort of closing down, the materials and device research, the hardware research, they were happy to get rid of that stuff.

Zierler:

Oh, wow.

Delfyett:

Right. Happy. So, I literally bought, physically purchased, all of the equipment in my laboratories at Bellcore for probably 10 cents on the dollar. So, I think my total labs might have been valued at about $300,000 worth of equipment or so, which are optical tables, some mounts, some oscilloscopes, spectrum analyzers, stuff like that. And I think I bought two labs’ worth of equipment — you know, two optical tables, and the scopes and stuff, and mounts for two labs, for like $30,000.

So, if $30,000 was a fraction of my startup package, so literally, for a small amount of money, I could buy two completely operational labs immediately. It was just a matter of spending the time to have the equipment shipped down from New Jersey, setting up the tables, and rebuilding everything on the tables, which do take time, for sure. It takes several months. But I was able to get up and running very quickly.

Zierler:

So Peter, now that we’re at the point in our discussion where you’re at the same institution that you’ve been at, I think that perhaps the most productive way to discuss your research over this time is if you can give me an idea of how you conceptualize the sort of — I don’t know what you would call them. Themes? Ideas? Concepts? Panels? You know, what are the basic areas of research that you’ve been involved in, that you see in separate terms? Obviously, it’s all related. Right? But what are the separate areas of research that you’ve been involved with these past 25, 30 years?

Delfyett:

Excellent question. So, it’s broken up into a couple of different components. Obviously, going way back to Bellcore, it was basically in the development of very short pulses with high power — sort of the compact, mode-lock, semiconductor laser technology. I’ve been involved in laser development for quite a while. As that has progressed, the laser development component of the research has evolved in areas of multi-wavelength generation, making these lasers work in new and unique ways. So, instead of just short pulse and high power, we’ve evolved that to making the lasers to emit multiple different colors at the same time. Another component of that has evolved into making what we call frequency comb lasers, or lasers with extreme timing and frequency purity. So, laser development, but the aspect of the laser development has evolved from not just short pulse and high power but novel types of functionality to extremely low noise and spectral purity. Other aspects have then been not just to develop the tool of the laser, but to apply the lasers for applications in communication and signal processing.

So, the applications have been for fiber optic networks in areas of wavelength domain multiplexing — we call that WDM; or time domain multiplexing, TDM. And also, applications related toward signal processing using the short pulse laser and precise timing as sampling for photonic assisted analog to digital converters. So, we build lasers, and then we apply them. So, even more importantly, I’d like to say that in my research, my research directions touch on the five M’s of photonics. And the five M’s are: we make the light; we modulate the light — put information on it, new types of modulators; we move the light — light transportation in the fiber optic — we look at how the property of light is distorted as propagation. Make, modulate, move, multiplex — adding different light colors together; and finally measure the new types of detection modalities. So, all of my research has worked in new ways to make laser light, new ways to modulate the light, new ways to add the different light colors together, coming up with new ways that we can avoid detrimental effects for moving the light from Point A to Point B, new ways to detect or measure light. Make, modulate, move, multiplex, and measure: the five M’s of photonics.

Zierler:

There you go.

Delfyett:

So, when people come to visit, and I say if you don’t remember anything when you walk out the door, and someone says: what did that guy Pete Delfyett do? I don’t know what he does, but I know he does the five M’s of photonics: make, modulate, move, multiplex, and measure.

Zierler:

There you go.

Delfyett:

If you can remember that, you’re good to go.

Zierler:

So Peter, let’s start with laser development. Can you give us a sense of a broad overview of where lasers were at the beginning of your career working on them, and how you have been involved in developing them into modern developments?

Delfyett:

Sure. To give you a feel, when I first started working with semiconductor lasers, the typical amount of energy you could get from one of these devices would typically be measured in units called picojoules. A joule is a unit of energy, and a picojoule is one trillionth of a joule — a very tiny amount of energy. But by the time — the most energy we could ever generate from one of these mode-locked lasers was about a microjoule, which is a million times more. So, from when I started, we went from short pulses of being a picojoule, to the most energy we ever produced was a microjoule, which was a million times more. So, that’s how much progress we have made in terms of the energy part. Regarding pulse duration, when I first started, pulse durations were probably maybe — call it 5 or 10 picoseconds. Now, we’ve been able to get pulses down to close to 100 femtoseconds. That is maybe a factor of 100 in improvement. A picosecond is a trillionth of a second, and a femtosecond is a thousandth of a trillionth of a second. Sorry about the scientific language.

Zierler:

No, that’s good.

Delfyett:

I try to define it as we go along. Regarding timing stability: when you generate these pulses from semiconductor lasers, even though the pulses come out pretty regularly, there are still some fluctuations or randomness in the timing. So, the pulse can fluctuate in its timing on the order of a few trillionths of a second. And I’ve been able to reduce that timing uncertainty into the attosecond regime, or basically have improved it by a factor of — let me just calculate here — hold on — probably by close to a factor of 10,000, improved the timing stability. So, that’s just in the laser development part. So, we have greatly improved the timing stability by four orders of magnitude. The pulse durations we have reduced by a factor of at least two orders of magnitude, and the power out we have improved by up to six orders of magnitude. [laughs] That’s where we started, and that’s where we have come. So, it has been lots of good improvement from my perspective.

Zierler:

And in terms of application, when you talk about application of lasers, how do you use the word “application”? Does that automatically mean a research context? Does it have a commercial component to it? Are you talking about patenting it? What does the term “application” mean for you, when you’re talking about lasers generally?

Delfyett:

“Application,” for me, literally means towards a real-world use. We’re going to develop a laser. This laser could be used for a fiberoptic communication system. This laser could be used for a photonic assisted radar system, where folks want to have better resolution in seeing the images they’re getting back from microwave radar. We can use light for that. So, when I mention — or, we can use these lasers to be applied in a new type of microscope that will be used for medical imaging. Literally, concerned with using these lasers for — so that the laser just doesn’t sit in my lab, so that someone else could actually use the light from the laser to make their experiment work better. Their experiment might be in the laboratory, or someone’s experiment might be part of a product that they’re trying to commercialize. And so, when I say “applications,” yes, I’m thinking for the laser to be used for a real world application. And for sure, if we think we have done something useful, we apply for patents. No question. I have 43 patents so far.

Zierler:

And can you talk about some of the legal or ethical issues surrounding applying for a patent that might have — you know, for a product that might have commercial viability, but that was created within the infrastructure of a public university? How does that work?

Delfyett:

Sure. So, when I apply for a patent, for sure I disclose that information to the University of Central Florida. If they decide to patent it, you know, we get together. We write the patent. I provide some input. UCS owns the patent. I am listed as the inventor. If money is to be made, there is some equitable sharing of money that is made from the patent. If UCS decides that they don’t want to patent it, they would return it to me. Then, I would absorb the cost for having it patented, and then if I wanted to start a company using that patent — which would then be owned strictly by me — I would then receive all of the money, or the company would be, or the venture capitalists would sort of own — would get some of the money based upon how the company is set up.

Zierler:

And have you ever pursued an entrepreneurial type of endeavor like that?

Delfyett:

Yes. So, as a matter of fact, one of the big DARPA programs we had was to see if we could take a semiconductor laser and drill holes in the wall. And when I first was tasked to do that, I said, “There’s no way we can do that. It’s impossible.” They said, “Well, we’ll give you a lot of money to do that.” And I said, “Well, let me think about it.” And I came up with a very unique solution. And that solution was the thing that resulted in improving the semiconductor laser energy by a factor of a million. That was — with that DARPA program, that allowed us to show that. And a company was spun out, and that company was called Raydiance. It was a real company. And that was the one that we spun out that was being used for making the short-pulse lasers for nonthermal ablation for use in cutting stents and fuel injectors and for modifying the Gorilla glass in the Samsung cell phone. We spun that technology out from UCF. Yes, we did.

Zierler:

I’m sure that when one of your inventions is adopted and has broad societal use, it brings you a tremendous amount of personal satisfaction.

Delfyett:

Yeah. It’s nice to know that you’ve had some impact. Now, for sure, Raydiance was successful for about 13 years or 15 years. It was ultimately bought by Coherent Laser, which is another major laser company. But the Raydiance as I knew it sort of no longer exists. All of its IP and technology was absorbed by another company. But it was something that was out there for more than a decade. It hired many people. I think they had about 85 people at one point in time. They were making lasers for, again, companies that made fuel injectors. They were selling lasers to Samsung. It was a real company. So, it was very nice to have done that, and more importantly, I believe having had that success had some influence in my ability to be able to be recognized with the IEEE Photonics Society William Streifer Scientific Achievement Award.

Zierler:

Yeah. So Peter, to bring the narrative up to the present day: what are some projects that you’ve been involved with over the past few years?

Delfyett:

Over the last few years? Let’s see. Right now, we’re trying to develop a two-color laser system. It’s basically two different lasers, which are both mode-locked, but producing short pulses. But this is going to be used as an input light to biological samples that would allow us to see what’s inside biological samples — certainly see what’s inside the cell, to take a look at cellular function in a three-dimensional way and monitor cell functionalities in real time. It’s called multiphoton confocal microscopy, and typically people have been using giant lasers, large solid-state lasers that fit on the size of a 10-foot table. But if we can make these lasers from semiconductors, there’s a possibility you can have these things in small, handheld, compact type of footprint, or potentially even inside your cellphone. So, this is the type of real-world application that I think about in terms of making my lasers. You know, applications for being included in a cell phone so you could take a cell phone and look at some spot on your skin. Is that thing melanoma or not? Or whatever it is. That’s one particular application. Another project we’re working on for DARPA is to try to generate multiple colors from novel —what we call microring resonators, and this would have applications in data centers where we’re trying to transmit information from one data rack to another, where the fiber links are only a few meters. But we’re trying to send bits of information which are beyond one petabit of information, which is — a petabit is 10^15 bits of information per second. It’s about — I can tell you in terms of Netflix channels if you give me a minute. A channel is 4 megabits, so 4 terabits is a million channels. So, if I went to 4 petabits, that would be a thousand times that. So, it would be like a billion channels all emanating from a piece of silicon circuitry in optics, which is about a millimeter square. A billion channels coming from a millimeter square piece of electronic circuitry. That’s one of the other big projects we’re working on right now. In addition to the novel two-photon confocal microscope.

Zierler:

I’m curious if — you know, it’s interesting to watch the whole scientific world come together to deal with Coronavirus. I’m curious if you see a place for lasers in dealing with coronavirus issues.

Delfyett:

Well, how about this? We all recognize — I wouldn’t necessarily say “lasers,” but optoelectronics for sure. So, let me give you a — let me tell you how lasers and optoelectronics have already impacted the area — our era of coronavirus is that there was no way you and I would be able to be talking through Zoom had we not made the investment in fiberoptic networks to allow this type of connectivity to happen.

Zierler:

There you go.

Delfyett:

That investment happened two decades ago, back in the early 2000s with the telecom boom. However, if that did not happen, all of the online teaching that we do now would not be possible. The Zoom meetings that we have — multiple Zoom meetings every day — that would not be possible. You know, the wonderful displays that we have on our iPhone, and the big, crazy watches and stuff, that stuff would not be possible. So, that is how fiber optics and lasers have contributed to technology today that we’re using with COVID. Now, we also know that optics is a great tool for spectroscopy — you know, laser light, light in the ultraviolet regime. The UVC band can be used to kill the virus. Ultraviolet light is well known to be a very good disinfectant, so I envision, as time goes along, compact LEDs that emit with ultraviolet light will be installed underneath the hand sanitizers, and the bathrooms will have these things proliferated all over the place. So, as far as novel optoelectronic — not semiconductor lasers, but optoelectronic semiconductor light-emitting diodes, which is the precursor to the laser — those things will be proliferated in terms of — as disinfectants for COVID. Similarly, the lasers can be used for other types of measurements and spectroscopic tools for trying to understand the virus. But those are two important ways, immediately, that optoelectronics and photonics has made an impact, or will continue to make an impact as we go forward.

Zierler:

Well, that’s good, because we need all the help we can get. Right? [laughs]

Delfyett:

Yeah, we do.

Zierler:

Peter, one aspect of your career we haven’t touched on yet is your role as both a teacher to undergraduates and a mentor to graduate students. And so first, in the undergraduate realm, I’m curious. What are the kinds of students that take classes that you’re teaching? What are their career aspirations, and what kinds of courses do you like to teach undergraduates?

Delfyett:

Sure. So, in the undergraduate curriculum, since we are in the College of Optics and Photonics, most of the optics and photonics faculty would teach classes as a part of the major for the undergraduate students. Let me explain it this way. CREOL, the College of Optics and Photonics, in collaboration with the College of Engineering, we offer a degree, which is a bachelor’s of science, a BS, in optical science and engineering. So, it’s a BSPSE: the Bachelor of Science in Photonic Science and Engineering. So, I teach an undergraduate class in the core curriculum, and that class is Laser Engineering. So, the only undergraduate students I see nowadays are students which are majors in the area of optics and photonics. Most of these students are getting degrees either in physics or EE, some even material science. I even saw one student was getting, I think, an MBA and took this as an elective course. But most students are taking the undergraduate — my courses, Laser Engineering, because they’re looking to be an engineer out in the real world. Some are going to graduate school, as an example. The guy who was doing his MBA, I think he maybe wants to start his own company, or certainly work in the laser field, but more as sort of a manager type — hence, him trying to get some technical background in the area of optics. Now, having said that, years and years ago, I would sort of team-teach a class over the summer which was Introduction to the Engineering Profession. And this was a course where high school students would come in between high school and college, and so students would take this introductory course to prepare them for the calculus and physics that they’d be taking starting in September. So, I’d get to see them in late June and July, and for six or eight weeks, kind of teach them how to be prepared and how to be organized and how to make sure they did their homework. And there, most of the students that I interacted with were from all areas of engineering: civil and environmental, mechanical and aerospace, electrical, etcetera — industrial engineering. So, that’s my role as a — teaching people at the undergraduate level.

Zierler:

And I’m curious, Peter. You mentioned before that it was sort of baked into the beginning of CREOL in terms of selling it to the state legislature, that this would be a boom to the regional economy. And so, I’m curious. As you follow the career trajectory of some of your students, if they had been able to forge careers locally, based on the education they’ve gotten at Central Florida, and with the rise of the industry in Central Florida — if you’ve seen those connections happen.

Delfyett:

Sure. So, the one immediate obvious case is that when we spun off Raydiance, we spun that company out in the research park. We had lots of people that were being hired from CREOL and my group there. Ultimately, that group moved to northern California near Sonoma Valley — Paloma, I think it was called. Anyway, so that’s one example. The sort of shining star example — again, there are many other spinoff companies that have happened are still in the Central Florida area — but the one that is probably, again, going to hit the grand slam is a company called Luminar. Luminar has gotten a lot of big press, and they are a company that is making the laser radar systems for autonomous vehicles. So, Jason Eichenholz was a first-year graduate student when I started as a first-year professor in 1993. He got his Ph.D. and worked at a couple of places, but now he is sort of the head guy at Luminar, which is located now in the research park right next to UCF. And they are, in fact, selling product, and they have a major agreement to be the sole provider of the laser radar systems for Volvo for their autonomous driving vehicles. If you look up “autonomous vehicles,” and different manufacturers and companies that do the laser radar systems for imaging, Luminar is going to be one of the shining stars. And that has been from a student that got his Ph.D. at CREOL, and I’m proud to say, I was on Jason’s Ph.D. committee.

Zierler:

Now, I know you have a very successful research group for your graduate students. I want to ask you first: how would you describe your style as a mentor to graduate students? Are you hands-on? Are you more hands-off? How involved are you in the day-to-day of what your graduate students are doing?

Delfyett:

Sure. I definitely am hands-on, only in terms of being my graduate students’ biggest cheerleaders. I encourage, encourage. I walk in the lab every day. How are you doing? Etcetera, etcetera. So in that respect, I am really involved daily. If they really get to a brick wall or are having difficulty, they’re more than happy to have me come in the lab and tweak knobs. And I, in fact, still do that. But I am not a person where I’ll say: okay, come in, let me do the experiment, and just have them watch all the time. No, I don’t do that. If I’m doing that, I’m training technicians. Right? You know, I don’t say: put the mount here. Put the mount there. Shine the light this way. Do that. Again, I’m training technicians. I’m trying to train scientists. So, I let them build the experiment, of course with guidance and advice, etcetera, but I don’t let my graduate students struggle and drown. You know? I like to be there, encouraging, but I’m not going to be a helicopter mentor and hover over them every second of the day. I might be more overlooking their shoulder for the brand new students, but just to sort of get them up and running, and typically even then, I’m encouraging the newest students to get their training from the most senior graduate students, because I want the most senior graduate students to have an opportunity to know what it’s like to try to share their knowledge and train people that are under them, because that is going to be something that’s required of them when they go to industry or wherever they go.

Zierler:

Now, I’m curious if the level of specialization that CREOL offers, and its stature within the community, is such that you might have graduate students that would be competitive at places like Caltech, MIT, but that want to come specifically for what CREOL offers. Have you had that experience?

Delfyett:

Yeah, that’s correct. And here’s the main difference between CREOL and, let’s say, a conventional physics or EE department. Let’s say you have a student who’s going to a EE school — pick any particular school — and they get to the EE department, and the student says: well, gee, I’m really not sure what I want to focus on. I could do control. I could do microelectronics. I could do power system component. I could do signal processing. I could do wireless. Oh, I could do photonics. Similarly, in the physics department, a person could go to the physics department and say: oh, gee, I could do astronomy, or astrophysics, or cosmology. I could do high-energy physics. I could do nuclear physics. I could do particle physics. I could do condensed-matter physics. Oh, I can do optics and lasers and spectroscopy. At CREOL, students already know that they want to do optics and photonics. So, there is already a filtering component that is in place, because people are applying to CREOL. Right? There is that filtering effect. For sure, most of the students — and because of that, we find that a lot of the students that are coming into our program are basically applying to places like University of Rochester and University of Arizona, which are the other two big major institutions that have a major optics program. Other big schools, like Caltech, Stanford, MIT, etcetera, they have good optics activities, but it’s just a much more limited set of faculty. So, if you go to a bigger school — I mean, one of the more well-known schools to do optics, the number of faculty you have to pick from is less, whereas when you go to Arizona or Rochester or UCF, you can do optics, but the number of faculty you can pick from is much broader. And the breadth of optical activities is much broader as well. So, that’s what we do definitely find.

Zierler:

Well, Peter, I think at this point in our discussion, I want to ask you, for the last part of our interview, a few broadly retrospective questions that sort of assess your overall career, maybe a few current events questions, and then a forward-looking question, which I always like to ask. So first, I’m curious. I mean, it’s such a unique opportunity, because you’ve been involved in so much research that has both basic science value and practical value. And so, when you assess your contributions to the field generally, do you tend to establish that binary in your mind of: here’s my research that has moved the science forward, and here’s my research that has moved the practical applications forward. Is that all one big jumbled research for you, or do you tend to think of those in separate spheres?

Delfyett:

For me, it’s going to be the one big jumble thing, because of the three-legged stool that I mentioned before.

Zierler:

Right.

Delfyett:

Again, I’m application pull. I look and see where the need is. That’s the engineer part of me. But in order for me to really solve that, to come up with a solution for that need, I really need to do the science first. I really need to understand that. So, in order for me to make a credible impact at that application level, I really need to do the fundamental science, to really see if I can come up with something new, because the only way you can sort of solve a problem is you have to throw something new and creative at it, because if you can’t come up with something new and creative, it’s still a bottleneck. Right? So, you have to do something new that someone hasn’t done before. So, for me, there has to be some more fundamental understanding of what’s going down on the bottom floor for science to be able to then say: gee, how can I exploit maybe some physical effects or phenomena that haven’t been looked at before? Maybe knowledge has progressed to a point where we know something more or better, where we can, in fact, exploit some new effect today when we couldn’t 30 years ago. That’s why it’s important for me to know the science, so I can build upon that to make a new device that can then be applied in the system. So, it’s one big jumbled thing for me, and I’m very honored to have had been able to make an impact in some of the fundamental understanding about the ways — mechanisms in lasers, but to apply those fundamental understandings to applications in communication and signal processing.

Zierler:

So, given that all of this research goes together for you, is there any one project that you’ve been involved in, either because of the way it’s moved the science forward, or because of its tremendous societal or market impact, that you feel most proud of? Is there anything that stands out, of all the things you’ve done, where you say, “You know what? This is really my magnum opus. This is really the thing where I’ve had the greatest impact, or my efforts played out in the best possible way I could have imagined”?

Delfyett:

Well, obviously this concept of eXtreme chirped pulse amplification, which was the big DARPA program that allowed us to spin off Raydiance, was a big one. This is sort of million-times improvement in energy. But when I first broke the records for short pulse and high power, for me, again at that time, that was such a momentous achievement for me, because to do anything at a world-class stage, where you could get recognition, was sort of mind-boggling for me. The XCPA concept that spun off Raydiance was truly a monumental concept for me. This other concept of using cavity engineering that allowed us to reduce the noise in lasers by a factor of 10,000, and stabilize, was a momentous contribution for me. And there’s another one about using an interferometer, a novel type of interferometer and injection locking, to make what I call a truly linear interferometer. I had this idea out of a dream. I swear to God. I was giving a talk and showing how I could use the different colors of the laser light from one of my frequency home lasers to basically synthesize or create a designer generated electric field, you know, like by Fourier synthesis, and I was using this way of injection locking an array of lasers to do that, which was, in itself, sort of mind-boggling. But this injection locking process would create some kind of modulation that was very unorthodox, and in fact, almost unwanted — not very linear. It’s almost arc-sinusoidal — is the phase response. And I gave a talk at a conference, and after I give a talk I’m exhausted, right, because I put so much energy into it. So it was basically, [laughs] you sit down, you have the lunch with everybody. And I was so burnt out and tired, I said, “Let me just run upstairs to my room and put my stuff down. Let me lie down for 15 or 20 minutes.” And I was saying to myself: gee, someone’s going to call you on this ugly phase response of the injection-locked laser. Someone’s going to say: gee, Pete, that thing is arc-sine phase response. That’s not even linear. Who the heck would ever even want that? How are you going to combine that light with your interferometer and make something that’s even useful? So, I was worried that I was going to get embarrassed by that. So I’m, you know, laying down on the bed there, and so apparently I’m thinking in my mind about this idea about the arc-sine phase response, you know, where this arc-sine phase response or injection-locked laser is in one arm of a Michelson interferometer — excuse me, a Mach-Zehnder interferometer.

And anyway, I fall asleep, and I wake up, and I say: oh, my God! This ugly arc-sine phase response of the laser, when it is in the interferometer, the interferometer exactly and perfectly cancels the arc-sine response, because the interferometer response is sinusoidal. Sinusoidal of the phase, and now if my injection-locked laser has a phase response which was arc-sine, the sine of the arc-sine cancels, and this response is perfectly linear. Holy freaking cannoli. This was like, euphoria. An epiphany. Wow! I mean, wow. And so, I immediately opened up the laptop, and I took out my simple math calculation program, and I programmed this thing in an interferometer to see if it would work, and adjusted some things — oh, that’s not right — adjust it here — boom! This thing came out perfect. And let me tell you, I sent an email — I called my grad student to tell him this epiphany that I had. We came back. We set the experiment up, and for sure, I have two graduate students that got Ph.D.’s working in that particular area. So again, when you talk about momentous things, there are several. The short pulse is one. The concept that we did to spin out the company for Raydiance was another. Making the lasers very low-noise, and this concept of the linear modulator — those were sort of like the four really big things which were ideas that came out of nowhere, because there are times where I’ve had these ideas where they just sort of pop out of nowhere to solve a problem, and I’m very blessed to have those instances of serendipity.

Zierler:

Now, it’s so obvious for you and for your intellectual development in your career, the impact, the positive impact that Bellcore had on your research — I’m curious. You know, we don’t have a Bellcore like it was during your time. When you see graduate students in your own mold who would really have their careers supercharged by being in that basic science environment, what options do you see available for them, circa 2020? Is there any analog to a Bell Labs, Bellcore kind of thing, for the 21st century?

Delfyett:

Yeah. So, those would be the government labs, like NIST, as an example. I’ve got a couple of students at NIST. Sandia Labs might be another government lab that works in the areas that I work in. So, that would be on the government level. I don’t know what the environments are like in terms of working at a place like Google Labs, as an example. I don’t know what that’s like — you know, how much of their research is really in hardware-type stuff. But Facebook has a lab. Google has a lab. You know, IBM is still around. Intel has a lab. But even Intel and IBM are sort of focused on their product, you know, turning a profit, where back in the days of Bell Laboratories, since there was a penny tax on everyone’s phone bill, your research really didn’t have to be focused on telecommunications. Bellcore’s was for sure, but there is no real analog to Bell Laboratories the way Bell Labs was in the old mold. But the government labs are probably the closest thing. NIST in Gaithersburg, or NIST in Boulder, Colorado, Sandia Labs in — are they in Albuquerque? I believe so, yeah.

Zierler:

So, it sounds like Bell Labs and Bellcore was truly a unique phenomenon, but there are still basic science opportunities where you can send your graduate students to do good work.

Delfyett:

That’s correct. Yes.

Zierler:

Right. Before we get to what I like as my last question, a forward-looking question, I want to spend a little time now on gaining your insights and perspective on — you know, it was only two weeks ago when we had #shutdownSTEM, and you know, the scientific response to Black Lives Matter, and as a response not only to the systemic racism and police violence that African-Americans experience on a daily basis, but an expression of the fact that these issues do not stop at the door in the world of science. And so, I’m very proud of — you know, the American Institute of Physics has been — played a leadership role in its team-up report in dealing with the issue of systemic underrepresentation of African-Americans in physics, and I think it has developed several novel and very constructive approaches to how we can fix this problem. One of the lessons, I think, to take away from #shutdownSTEM was that it wasn’t just a day on the calendar — that the point is, is that this really needs to be an ongoing conversation, because the problems are not going to go away just by taking a day off for reflection. It should really be a day off for reflection and then using that, the momentum of that day, to really push the field in the most positive and productive way possible. So first, I want to ask you: over the course of your career — and these are obviously very difficult things to quantify — but do you think from even your days as an undergraduate in New York, has the world of science become better or not for people of color?

Delfyett:

I think it has become better for people of color, and — let’s see. It has certainly become better for people of color, because as time goes on, there are more people of color that are getting into positions in academia and industry and are being recognized and can serve as mentors for other folks from underrepresented groups come through. That evolution is occurring at different rates in different disciplines. So, for example, I think the number of minorities in the areas of engineering has increased more rapidly than the number of minorities in the areas of physics, as an example. So yes, there are more Ph.D. physicists who are Black, and women, as an example, today than there were 30 years ago. But that’s going slower — the numbers are increasing slower than what you would see in a computer science department, chemistry, biology, engineering, etcetera. Minorities are folks in underrepresented groups, and those areas of STEM are increasing at a more rapid rate.

Zierler:

What do you think explains that?

Delfyett:

Very simple. Physicists were trained very much with the kind of style where — older physicists, for sure — with, [deepens voice] “I had to struggle. You must struggle, too.” [laughs] Right? There’s not a lot of warm hugs and embracing, and physics is not like that. Right? It is not like that. And so, when you’re from a community of folks which is typically underrepresented, and you may feel less secure about what your capabilities are, being thrust into an environment which is less warm, colder, an environment which is, “I had to struggle. You must struggle too,” is daunting. It’s a little daunting. Now, for sure, I’m not saying engineering is not like that, but I think just because there have been — because of that, I think that has been a barrier for folks to go into physics. Also, here’s another thing. Physics is an excellent undergraduate degree for going to graduate school. You know, physics for sure is a very broad undergraduate training in math and physics. You get some quantum, statistical mechanics, you know, classical mechanics, etcetera, whereas in an engineering discipline, folks come out with an engineering degree and actually can be hired as an engineer. Folks typically, as an undergraduate degree in physics, are not necessarily going to be hired to do physics, which is why I basically say: physics is a great degree for graduate school. So, many times, people will get a physics undergraduate degree, and if they’re not going to graduate school in physics, and they are going to graduate school, it’s going to be in a discipline other than physics — patent law, or whatever it is, MBA, etcetera.

Zierler:

But these — Peter, just to be clear —

Delfyett:

So what we tend to do is we tend to lose students that way as well.

Zierler:

But just to be clear, the issues that you’re describing are essentially colorblind, in the sense that, you know, what a physics undergraduate degree can do, that’s true whether you’re Black, white, Asian, whatever.

Delfyett:

That’s correct. But my point ultimately is to say the things like that, I think, then — you know, smart undergraduates, if you’re people of color or not, I’m going to say: well, gee, would I do an undergraduate degree in physics or EE, I might choose EE because I think I might be able to get a job better. So, in terms of trying to attract — again, that’s an issue independent of color, but again, issues of color — again, if you’re coming from maybe an educational background where things may not be as easy. Maybe you’re coming from a two-year college. You know, your math skills may not be as great. Whatever it is. I don’t know. If you’re feeling a little insecure, and then going into an environment where the general environment is: I had to struggle; you have to struggle, too. That little bit of insecurity just is an extra amount of weight. And that’s how I think the students may receive that, even though the faculty — you know, that just may be their demeanor. They just may be — pardon the expression — grumpy old men, because that’s how they were trained to be.

Zierler:

Grumpy old white men.

Delfyett:

Grumpy old white men. Exactly.

Zierler:

So of course, this all begs the question: if the starting assumption is that the issue of underrepresentation is problematic, the assumption is that physics is good for underrepresented groups, and underrepresented groups are good for physics. Right? That it goes both ways.

Delfyett:

Right.

Zierler:

So, if that’s the starting assumption, it begs the question: where do we go from here? How do we begin to address these broader issues, so that these disparities are not so apparent going into the next decade or two?

Delfyett:

Sure. Well, certainly I think the mindset of a faculty have to be a little bit different, and it’s a very simple mindset. I can recall when I was an undergraduate, even in engineering — I forget. I was in an intro to engineering class, whatever it was. It was in a room of 300 people, and the guy in the front of the room says: look to the left, look to the right. In four years, two of you will not be there — of the three. Right? [laughs] So, I’m looking at both. I’ve got a good friend here, and a good friend there, and I’m like, “Oh, my God. I’m hoping it’s not going to be me, the one that’s going to be missing.” [laughs] And so, they have that attitude, so many faculty, when they teach their course, they teach it in a way to try and figure out ways to weed people out, to fail them, to sort of make the width of the filter narrower to prevent people from getting through. That mindset has to change. So, my teaching and everything I do is to go against that mentality. My style is to be embracing, to figure out what I can do to help people to get them through the course. And when you have faculty operating in that way, it shows the students that the faculty cares about them. It cares about the student learning. It cares about the students’ success. And when a student sees that the faculty cares, like Alfano calling me a “turkey” — I thought he cared — this makes the student engaged. That’s where the difference is. The faculty has to be approachable. You have to be approachable and embracing, and that’s my personality: to be approachable, to be caring, nurturing. That goes a — it works wonders. It really does.

Zierler:

It’s everything.

Delfyett:

It’s everything. It makes you feel like you’re part of the team. Right? If everything is cold, and if you make people struggle, it makes you feel like you’re not a part of the team. It makes you feel like when you open the door and you see everyone studying for your class, and you weren’t invited, it makes you feel like you’re not a part of the team. Right?

Zierler:

Yeah. Peter, I think for my last question, I want to ask — you know, you’re brimming with excitement for so many different things. I want to ask specifically, in terms of the constant problem of: there’s only so much time in the day. There’s only so much funding to apply to a particular topic. Right? How do you want to, for the remainder of your career, most productively apply the resources available to you, to make the biggest ongoing impact, both for society at large and for moving the field forward scientifically?

Delfyett:

Right. How about this? That is an easy question, because my biggest impact — while I think the things I’ve been able to do in the laboratory, whether it’s things that I did or things that I do with my students — the biggest, most lasting impacts are my students, literally. When I create Ph.D.’s, they’re going to go out and carry the legacy that I was trying to develop. Hopefully they will carry the kind of research environment and style, the lessons that they learned from me — even when I teach class to the undergraduates, these are the seeds that I plant which will go forward and have impact. So, my students, whether they’re my graduate students or undergraduates, those are what I’ll call my second-order impact effects, as opposed to first-order impacts, which are results, papers, patents, companies, etcetera. But as my career continues to go, I will still continue to try to do the best I can in terms of my research, whether the funding is coming from NSF, or DARPA, AFOSR, NIH, whatever it is, companies, etcetera, I will still continue to try to train my students to be the best, to do the best possible work. But also, I recognize that my impact in terms of being a role model and being excited and trying to teach the best way I can and to get students to learn in the class, is also another important lasting impact. And even if it gets to the point where funding dries up, and I don’t want to do research or can’t do research anymore — which hopefully will never happen — I’ll still be able to hopefully have the passion and excitement for the field of optics and photonics and for teaching. And that impact, I hope, I’ll be able to continue to do for the rest of my career. I’m not planning to retire at 65. I’m not planning to retire at 70. You know, it might cross my mind at 75. We’ll give it some thought at that point.

Zierler:

Well, as I’m sure you know, physicists never retire, so — [laughs]

Delfyett:

That’s correct. That is exactly correct.

Zierler:

Peter, it’s been so fun talking with you today. I’m so happy we were able to connect, and your insights and perspective are of tremendous value. And I really appreciate the time you spent with me today.

Delfyett:

Thanks, Dave. It’s been a pleasure for sure. If you have any additional comments or questions, or things you want to clear up, or if some of the things which I’ve said didn’t come out clearly on the recording, please feel free to give me a call or send me an email, or set up another Zoom link — whatever I can do to help you. Again, my job is to make your job easier.

Zierler:

Thanks so much.