H. John Caulfield

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Interviewed by
Sean Johnston
Interview date
Santa Clara Conference Center
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In footnotes or endnotes please cite AIP interviews like this:

Interview of H. John Caulfield by Sean Johnston on 2003 January 21,
Niels Bohr Library & Archives, American Institute of Physics,
College Park, MD USA,

For multiple citations, "AIP" is the preferred abbreviation for the location.



Interview discusses Caulfield's career in holography research, his positions held in many companies, his role as the organizer of the first Gordon Research Conference on holography, and his collaboration with peers such as Dennis Gabor, Adolf Lohmann, Ralph Wuerker, and Emmett Leith.


Getting into holography: A time in the mid-60s when science was well funded. The only way to manipulate me is to say “this is something you can’t do”. His thesis advisor was an academic snob who said “you’re too smart to work in industry” — went to work for Texas Instruments, near Dallas. First work he did was on thermionic energy converters — Dennis Gabor had invented them. TI decided they couldn’t make money at that, so they asked him to cast around for another area to study, rather than merely firing them as they would today... Saw an article by Leith and Upatnieks in Scientific American. Invited them down for a talk; Leith came down to Texas. Many years later met his counterpart, Denisyuk — equivalent people: very bright, extremely modest, wonderful human beings. Leith has a bizarre, off-the-wall sense of humor. John has embarrassed himself when Emmett says something deliberately funny. John got into the field as a result of that talk. Made the first holograms at TI. Had a long career in which he has never completely lost that field. Saw his first hologram when Leith brought the hologram of the toy train.

Rest of audience was the scientists at the research lab, and all were thrilled and shocked — to produce an image like that. One of the things Caulfield did at TI was invent ‘local reference beam holograms’ — deriving the reference beam from the object beam. Many others have invented essentially the same thing in other fields — e.g. Tom Cathey at Univ. of Colorado independently invented it, he found out years later. In interferometry it’s called the Smartt interferometer.

At this stage was his first encounter with George Stroke — about 1968 or 1969. The VP of Research at TI called John in. Said “Dr. Caulfield, a serious charge has been made against you — someone claims that work just published was stolen by you” Caulfield already knew of Stroke. The VP said it was Stroke. Asked the VP if he knew who Emil Wolf was (wrote book with father-in-law Max Born). The OSA had been casting around for someone to review Stroke’s book. No one would touch it in the field. The word was that people were afraid to say in public what people wound up saying. Caulfield told the VP how he could explain the position — he got Wolf’s review of George Stroke’s book — and read the last sentence: “I invite the reader to consider what would happen if all books were written like this one — to steal credit”. Many people don’t like Wolf — because he is candid and not afraid to say what’s on his mind. So he sent a telegram to “Dear Prof. Stroke — sorry to hear that my publication covers work that you’ve done — give me the proper reference to that work, and I’ll try to get it published.” Stroke said “didn’t mean that — it’s something like what I’ve already discussed.” He did this to many other people — victimizing others.

Stroke was involved in victimizing Gabor. After Gabor’s stroke, George Stroke took him under his wing and showed him around — this is before the Nobel Prize… George was basking in Gabor’s glory, and Gabor wasn’t himself… exploited, according to Caulfield (doesn’t want this opinion attributed to him). Wants to get off the Stroke stories — there are many of them.

Sun Lu was a colleague, younger worker. He left TI before HJC did, and left the field, although did good work with him. While in Dallas, HJC daughter was born — embryonic eyes — One absent, the other malformed. Three choices: stay in Dallas (still fighting immigration, so all handicapped children put into one school); two states mainstreamed children with handicaps. She was extremely bright. Those states were Massachusetts or California. He opted for Massachusetts. They spent 18.5 yrs. there, where he worked for Sperry-Rand in R&D. That took up 1/4 of his career. For Sperry Rand he did work on display holograms — making a transmissive hologram of an object very close to the plate. Dominic De Bitetto, retired and is in seclusion, was brilliant, and set the basis for Benton’s later rainbow holograms. Then went to work for small company R&D — Block Engineering and Aerodyne. Lots of Block stories — Larry Mertz was flakey but brilliant. Myron Block was wilder than anyone may have heard — need to publish a Myron Block book. Spent about 5-6 years there, doing FTIR for a while.

Published a paper about 10 yrs. ago with Abramson and Bjelkhagen — ABCs of time coherence recording in holography. Tries to tie temporal, spectral and spatial aspects together. Did a little bit of holography there — spatial filtering (a specialty for HJC) and temporal domain imaging. Myron is still alive and kicking, and Block still appears to be going too. Invented and demonstrated (at TI) optical coherence tomography. This was about 1967. (He can supply his resume). About a year later or so, Yuri Denisyuk invented the temporal version of this — time-gating.

He is very unhappy with Nils Abramson who came to visit him — Yuri claims that the ‘light in flight’ stuff is the term he used, and that Abramson borrowed them from him. Nils Abramson improved on it and took it much further, but anyway... Yuri and HJC did this gating subject years before everyone else. Now being done with low-coherence-length LEDs, instead of 6-8” coherence length HeNe lasers. Then worked for Aerodyne research, also in Boston area. Another small company. This was the second phase of his career — working for small firms. At Aerodyne he worked on pattern recognition — made first computer-designed pattern recognition mask. Bill Maloney worked on it, and Henri Arsenault improved it. After that did generalized matched filters — not primarily holography. Another event: last of his parents died, and he had freedom to move. Three universities were looking for directors: University of Dayton research institute (a religious school, and could not be paid more than the president, who was monastic!); University of Arizona optical sciences center; Peter Franken had just died; spoke to Bob Shannon, who was another candidate. Asked if he would stay if HJC came, and he said he would leave, so HJC withdrew. The other was University of Alabama at Huntsville, wanting to start a new optics centre. He went to the U of A. Moved across town after 5 years; wife had sheep farm “Far Out Farm” — 300 sheep and 4 horses half-way between Huntsville and Nashville. Moved across town to Alabama A&M — spent a further 5 years there as ‘eminent scholar’. That is the 3rd phase of his career.

Last phase is ‘unemployed’ — many jobs, many universities, not for profits, chief technical officer of several small companies, and does consulting. At this stage in his career, no one wants him full-time. He causes trouble — generates more ideas than they can follow-through on. Very creative and fertile! Turning point in his career: turned from being a good scientist to being non-competitive, competing only with himself [TJ passed by — who had paid for him to attend...] ‘Caulfield number’ — the number of papers people write with HJC — highest number is 4. i.e. many collaborations. Has not co-published with either Yuri Denisyuk or Emmett Leith. Has edited a festschrift for them, though. Out by the end of 2003. Joe Goodman; Tom Cathey; Francis Yu; several Russians — Petrov, Michaelian; Joe Shamir (Israeli) Adolf Lohmann has the same approach — should talk with him. One of the special people in holography whom HJC reveres. Stroke was good for the field — after Stroke, when someone comes in our field and misbehaves, someone takes him aside and tells him ‘you don’t do that in our field.’ “Once we got Stroke out of the country, it has been populated only by nice human beings”. Patent disputes on the commercial side, but not where most of the scientists work.

HJC has been called as an expert witness — he hates that. A lot of ugliness at that level. A lot of people whose feelings are hurt. It will go on and on and on. Can’t have the attitude HJC has about science, about money. If you are able to pursue a commercial direction, others can’t; it’s a zero sum game. Unlike science, where there is no limit on intellectual achievement. Sees the field divided between science, commerce and artists. Borderline people include TJ and Benton, between art and science. Some of the uncredentialed artists have made wonderful contributions. HJC hasn’t collaborated at all with them — has no sense of art. Has taught many to make holograms, but “things break when I enter the laboratory”. About 15 yrs. ago, Byte magazine had mentioned various people as influential in computing, including HJC — he didn’t have a computer then.

He is happy doing proof-of-concept work. Sees himself as a bit like Michelson, and Pauli — can’t experiment or program, but can think and invent, and see connections that other people don’t see... Nearly always worked on his own — his wife now wants to move to Montana — it makes no difference to HJC, because he can work anywhere and collaborate as before. Are meetings a way of networking? HJC says his ‘anti-particle’ in holography is Joe Goodman — everything true of him is false of HJC, and vice-versa. HJC seldom goes to talks, unlike Goodman who takes notes on even poor talks. Meetings for HJC are for networking; getting to know people; people are what’s lasting.

The important ideas in optics have changed over the years, but the important people are Wolf, Lohmann, Denisyuk, Leith... First met Denisyuk about 1983 or 1984. HJC was invited over, because they had translated a book he had written. The KGB person who met important westerners admitted that everything is bugged. He wasn’t the primary person HJC was visiting, but couldn’t meet Denisyuk in his classified lab; had to see him in lobby. Years later had a hologram made within that lab. Says Denisyuk and Leith were both working on side-looking radar and optical processing — exactly parallel. Both decided that digital computing wasn’t good enough, and that they had to do it optically… HJC may have been the first to introduce the two. HJC chaired the first Gordon Research Conference in 1972, and brought Yuri in for it.

Between Gabor, Leith and Denisyuk others were working. Albert BAEZ was a great scientist — first director general of UNESCO — so Joan Baez is connected in a strange way. In England, one was Gordon Rogers. HJC never met BAEZ. Others were HMA El-SUM and Lohmann. Denisyuk white-light holography: Caulfield “immediately” was aware of it when published. Thinks it was published and widely known soon in America. Holography suits the Russians — like bizarre and exotic things — polywater, ESP, and holography struck them similarly. They also have a sense of the aesthetic and beautiful — and here too holography fits. And a Russian had played a credible role in it, so the subject really took off. Ken Wilber's ideas — for some reason this didn’t appeal to the Russians. They emphasize the hard physics of it. HJC’s paper on the ‘holographic mind’, which Leith said he admired him for writing, criticizes this theory. HJC became friends with Karl Pribram — they work in similar fields (perception, consciousness) but not in holography. Walter Friedman, his best student, said “Don’t talk to him about criticisms of holography — he doesn’t want to hear it.” HJC hates to see his field subject to popular books make it obscenely foolish. People nevertheless approach HJC about these bizarre aspects. Karl is ‘part of the problem.’ The other major contributor was David Bohm — brilliant and flakey. ‘You learn nothing from these analogies’. Never met Bohm, but knew Pribram through his own work on perception and consciousness. Has discussed holography with him, but Pribram won’t back down... he’s a very nice man.

Lohmann did computer-generated holograms in 1960s. Yuri Denisyuk and HJC described the ‘Michelangelo theory of holography’ — ‘just look at the block of marble and chip away everything that isn’t the object’ — the block of marble is the beam of light. A hologram removes all parts that don’t belong to my face, or your face, leaving the face itself. Lohmann used that same trick, although not expressed as colorfully as that, to write computer-generated holograms. He imagined light coming in at an angle; fixed in time, wave front after wave front makes a slice. The hole marks the phase, and the size of the hole governs the amplitude. So writing dots can create a phase and amplitude record. After the fact it’s obvious; before it, however, contention rules. Direction of holography during his years: “a bit like artificial intelligence”. The real workers in the field always complain that people say aspects are impossible, then they get solved, and keep changing the goal posts.

Aspects in holography have become completely routine, e.g. security holograms. Leith and HJC once propounded ‘folk theorems’ in holography, boiled down to one: “Holography is the best way of doing anything in optics, but also the most expensive”. Gene Dolgoff in NY makes lenticular full color images that are magnificent. “I don’t even know what holography is. We debate it. God didn’t create very many categories. Humans created them.” “I do not regard holography as inherently interferometric. Gabor had three inventions: all are still in use. The first was the most important. You could record a wave front and if you could subsequently recreate that wave front, you would see a three-D image. That’s a brilliant invention, and the essence of holography. His second invention was the Michelangelo trick: that interference was a good way to record a hologram. And the third invention was the particular way he did it, and even that hasn’t completely vanished…, using a dilute object, most of the light went straight through as the reference beam.”

Lev Landau kept the world from discovering holography for years. Landau and Lifshitz book on theoretical physics: Not a word is due to Landau; not a thought is due to Lifshitz. They talked about light scattering. Imagine a particle here, scattering. Some of the light or electrons or whatever are scattered. But don’t look where the direct beam was hitting, because that will cause confusion: look outside the beam. Gabor won the Nobel Prize for looking inside the beam. All the theoretical physics books portrayed the Landau and Lifshitz line. More often than not, the Russians really did invent most things. One of the greatest scientific cultures that never had the equipment or the freedom. American holography has gone off on various tangents. Holography is the father of many fields, all of them small. The father of scanners; holographic diffraction gratings. Stroke got started with diffraction gratings working at MIT with GR Harrison. Harrison was on sabbatical the year that Stroke graduated. He was later surprised to discover that in the Handbuch der Physik, Stroke had stolen Harrison’s notes as his own work… Holography doesn’t seem to have overwhelmingly important uses. He now knows why ultrasonic holography isn’t very good, so will now try to make it better.

Folk theorems: can’t recall them all now. Funny stories:

• Dennis Gabor had a dog — All Gabors are Hungarian, and all are embarrassed by the Gabor sisters. Gabor had two female dogs (bitches) — Eva and Zsa Zsa.

• Adolf Lohmann meeting Denisyuk for the first time — went through customs there. Got to his briefcase and found his papers and a few holograms. They wanted to see the ‘holograms’ — you can’t really see them well here... they took them in a bag and sealed it and had to go the next day to the police to explain why he was bringing holograms into the Soviet Union. Denisyuk and the KGB official, when Lohmann left, laughed and explained the word for hologram is Gologram — and a word like ‘hologram’ means ‘pictures of nudes’ or pornography…

•New York City Cattier’s hologram of a dangling diamond necklace. Says he and the owner of the shop were watching on the day it was put on display. Traffic came in spurts and empty periods. Groups came and went. A bag lady there during a quiet time, made grabs for the necklace, then shook her head and walked away.

• Ralph Wuerker and Bob Brookes had invented one kind of holographic interferometry. He made holograms of statues all through Europe. One of his was in Denmark; those in Copenhagen are enamored of the story of the lost prince, found urinating in the stream. So he recorded the statue and a real image of the stream was coming out. A lady was watching this one, walked in the stream, and looked in horror — thought the light was real liquid.

• Many funny stories involving Emmett. Dalabar Kvetkovich (?) working at Institut Louis Pasteur in France. Was working in Dubrovnik, Yugoslavia. Lloyd Cross brought a hologram. Customs people saw a cylindrical hologram admiringly. Everyone thought it was wonderful. Then he started to leave the country and return to Japan. On leaving the country, he couldn’t leave with it because it hadn’t been declared in customs. Finally Dalabar sold it to Cross for $1 to get it out.

• Gabor’s Nobel Prize: Eric Inglstrom was being interviewed for Swedish television. Said they were good for optical testing, for making 3D images, etc. One of the most wonderful things is that you can hit it with a hammer into a thousand different pieces and each will create an image. They cut his interview at the “pieces”, changing the images! HJC has been misquoted in the NY Times, etc… hopes to see a transcript of this discussion. Now almost ashamed to tell people he works in field of holograms because of the misunderstandings amongst the public. However, a lot of the science fiction portrayals should soon be possible — but won’t be holography. Holography is a stimulus to science and technology — a stepping stone, or means to an end. It will continue in little niches here and there.