Larry Siebert

Notice: We are in the process of migrating Oral History Interview metadata to this new version of our website.

During this migration, the following fields associated with interviews may be incomplete: Institutions, Additional Persons, and Subjects. Our Browse Subjects feature is also affected by this migration.

We encourage researchers to utilize the full-text search on this page to navigate our oral histories or to use our catalog to locate oral history interviews by keyword.

Please contact [email protected] with any feedback.

Image not available
Interviewed by
Sean Johnston
Interview date
Ann Arbor, Michigan
Usage Information and Disclaimer
Disclaimer text

This transcript may not be quoted, reproduced or redistributed in whole or in part by any means except with the written permission of the American Institute of Physics.

This transcript is based on a tape-recorded interview deposited at the Center for History of Physics of the American Institute of Physics. The AIP's interviews have generally been transcribed from tape, edited by the interviewer for clarity, and then further edited by the interviewee. If this interview is important to you, you should consult earlier versions of the transcript or listen to the original tape. For many interviews, the AIP retains substantial files with further information about the interviewee and the interview itself. Please contact us for information about accessing these materials.

Please bear in mind that: 1) This material is a transcript of the spoken word rather than a literary product; 2) An interview must be read with the awareness that different people's memories about an event will often differ, and that memories can change with time for many reasons including subsequent experiences, interactions with others, and one's feelings about an event. Disclaimer: This transcript was scanned from a typescript, introducing occasional spelling errors. The original typescript is available.

Preferred citation

In footnotes or endnotes please cite AIP interviews like this:

Interview of Larry Siebert by Sean Johnston on 2003 September 4, Niels Bohr Library & Archives, American Institute of Physics, College Park, MD USA,

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


This interview discusses Siebert's early career at North American Aviation, KMS Fusion, and Conductron Corporation, as well as his holography research leading to the first holograms of living subjects.


Sean F. Johnston is from University of Glasgow, Crichton Campus, UK Siebert was an electrical engineer at Conductron Corporation, Ann Arbor, in the late 1960s and produced the first pulsed laser for hologram portraits, creating the first human portrait of himself.

Had accumulated a list of publications. Born near Salina Ohio, May 3 1938. Studied electrical engineering at University — went in as a general engineering student. High school had a teacher – Mr. Deal — who encouraged him to go to college. Got him into Elim College in Indiana, then Ohio State University. He moved up to Michigan because it had a good university, and wanted to keep studying — got Master's at OSU, but Michigan was 'so far behind what I was doing at Conductron' that he gave it up.

He worked a couple of summers before — New Ideas Company in Coal Water Ohio, about 6 miles from Sauna. The last summer he went to work for North American Aviation in Columbus Ohio. After graduation he went back to North American for about 5 yrs. He started in an electronics design group, but his advisor for his Master's thesis found nothing in electronics -lasers had appeared, so he got a job with Dr. Horscht to build a laser diode communications system, then laser distance measurement for large antennas. Haystack antenna at MIT was about 30 ft. diameter, inside a radome. Had a theodolite to measure the surface and adjustments all around it — turnbuckles.

They went out of the antenna business, and he looked for other work.

A guy from North American came from the Willow Run Labs — the guy said "it's a good place to be from". Ann Arbor 'was a good town at that time — it was mostly Lutheran and I grew up Lutheran, and it just seemed a good conservative town". He came up in 1966, and his papers started to appear in 1967.

Kip Siegel, formerly a director of Willow Run Labs at U of M, started Conductron. He had a lot of "new ideas on radar cross sections of all kinds of things - missiles and that kind of thing — and he started Conductron based on that kind of technology."

'He was hot on holography at that time, because it was kind of a hot subject, and he was one of those guys that can go out and sell anything.' He was talking about holographing the 1980 (?) Olympics, so I came in as a guy that had some experience at North American in lasers, and we had bought up big Conrad lasers before I left (ruby pulsed) so I got in on that project of making these lasers that was coherent enough to do holograms — it had to be single axial mode, and single transverse mode.

He was reading all the journals there was on laser technology 'and now I can't read half of them' and 'got some ideas on mode selection, and nobody had really worked on one to make it coherent for holography'. They were talking about etalons for picking out the axial modes. (9.00) Went to Conrad in California, and bought a Conrad ruby laser — about one pulse per 2-3 minutes, after charging the capacitors. Had 112 and 3/8 ruby rods — would put out good amount of multimode energy in a single pulse. He tried to get enough coherence in the transverse direction — went down to an aperture 2 mm beam, and aligning it to get a single mode — a matter of optically aligning it. He did use etalons too for mode selection of the axial modes. This process took about 6 months. One of those 8 to 6 or 7 o'clock in the evening jobs.

He used etalons at the end to measure the spectral characteristics, but 'we were in a hurry and wanted to get something that would make a hologram of something moving'.

He was serious about the Olympics idea. A little while after he sold Conductron for perhaps 3 million dollars to McDonnell Douglas. At a stockholder's meeting he got into an argument with James McDonnell and his technical advisors, who said you couldn't make a holographic movie. So Siegel bet a hundred dollars. He came back with Bob Buzzard — Siegel's immediate boss at Conductron — bought a 35 mm film projector to advance the film, and spent nights with a filling station model and made a motion picture by animated frames using HeNe lasers. They worked on it at 3 am to avoid interference from traffic and other noise. They showed it to James McDonnell and he had to admit that it was a movie. Had a party at Gar Bush's house (?) on that hundred dollars.

Siebert made the first pulsed portrait of a human — himself. Had made a hologram of his hand initially. Did people comment on it? Not so much from the outside, but from the inside it was a big deal.

Quite soon after — maybe a year — he made the hologram of his face. They had moved from one building to another, having 5 big holographic labs with granite slabs for stability. These were for production holograms. All the buildings were on Plymouth Road. (Ave Maria Law School now occupies the area.) The old main building was on the comer. He doesn't seem to have been near there for some time. For a while it was a sanitary regulation building or something. Up further back a couple of hundred feet away was the newer building, where he did the holographic portraits.

A thrill the first time? Yeah — was expecting it — the other guys were making holograms all the time with HeNe lasers. One of the first things he did was a calculation of how much energy you'd need from a wall plug to make a holographic movie — something like a million watts, he estimated, because of laser and film inefficiency. Things like that didn't bother Kip. He was talking about 3D TVs too, although everyone realized that depth perception was gained because of movement more than binocular vision. Perception of depth depends on focusing and other factors too.

He had gone through calculations for safety too. His single mode laser oscillator, about a meter long, was putting out only a few millijoules. Then a few passes through one amplifier, and then a second — producing up to 10 joules. If you look at a 10 centimeter dia beam on a diffuse surface, scattering out (lambertian reflector) you could observe it safely with your eye. He made a transmission hologram of himself, and a reflection hologram of Dick Zech.

Shows IEEE paper — 'Life size hologram of a human subject'.

Had been a member of the IRE — Institute of Radio Engineers — from undergraduate days, before it became the IEEE.

Did a lot of pulsed portraits after that. One evening he got together 10 guys around a table in one of the big labs, and made a hologram — all people at the lab. He probably has a photograph of that, and has appeared in a few books.

Did he do all the pulsed work at Conductron? Practically. Some were made by other people, but there weren't many — Henry Hantz. The laser oscillator was terrible to align. The laser rods were imperfect optically, and it took a week of effort to find a good transverse mode, and temperature variations were a problem, and the mirror mounts did not provide independent movements of axes, x affected y. So it took 'plain old experience and patience'.

That's why he was as successful as he was — he had the patience and diligence to make it work.

He did it from 1967 to 1972, until the move to Missouri. He went down for a week or two to help set up the laser, granite slabs, etc.

Kip had left to found KMS Industries, but some good salesmen had stayed behind, and they convinced McDonnell Douglas that holography was a burgeoning field. At Ann Arbor, Conductron had maybe 20 people — including secretaries, production workers etc. — doing holography. Perhaps 4 people comprised the scientific bunch. They used to buy boxes of Agfa Gavaert and Kodak film — probably several hundred boxes. Mostly 4x5 plates; the portrait of the 10 people was 8x10, he thinks. Probably made about 100 8x10" holograms; some on sheet film 10" high wrapped in a circle, making holograms of 'female employees there, illuminated from the top.' About 4' diameter — it didn't tum out too well, because the beam from the top was linearly polarized and most of the radiation coming off was diffuse so depolarized, so it was darker in some areas because of the polarization difference of the two beams. He recalls an optical society meeting in Detroit showing a hologram of somebody blowing a kiss (presumably the Multiplex hologram … he's confused about details).

They had 3-4 marketing people who had sold Hoffman LaRoche, a medical/pharmaceutical company, on the idea of making holograms of body parts that their body parts would be used on. Some were pulsed, but the main ones were HeNe holograms of plaster models.

Made some for airports — front lighted things, using tungsten halogen bulbs with filters.

He was with Conductron while it was in Ann Arbor. He was going to move the family down — wife pregnant — but wanted to stay here despite offers from Boeing on West Coast and RCA on East Coast. Had put the house up for sale, but a friend from Bendix, Howard McDivott (?), said Bendix was hiring people, and they were doing multi-spectral scanning from aircraft. They were doing well at that time, and had a separate group on Jackson Road — 5 miles west — doing earth resource projects. So Siegel got into that, working on low-noise photodiodes and circuits to put into the scanners. The visible spectrum was divided into perhaps 10 regions by filters, and the IR, and blackbodies for calibration. When in on one Saturday, he hooked up the thermoelectric coolers and it burned out his circuits with 10 sensors — very expensive! He was just about fired for that. He recalls? Wilson, a manager there, showing him what happened, and Siegel took the same connector and put it on the same connector as before — even though polarized connectors, you could still misconnect them — so it was shown not to be Siegel's fault, just bad connector design.

When he went to Bendix, he was finished with both pulsed lasers and with holography.

Went to work in Bendix in 1972, but they started losing contracts. They went down as a result. Siebert wanted to get into other things. He went to an electrical engineering conference, and was advised to go work for KMS if you wanted to stay in Ann Arbor — thinks it was Chihiro Kikuchi. One of his friends from Conductron — Sandy Thomas — went with Kip to KMS Industries.

When Siegel split with McDonnell, he took Sandy Thomas, Lou Cutrona and 5 of the top people to found KMS Industries. Did that hurt Conductron? They made the portraits after Kip left, in the new building. Kip Siegel met Keith Bruckner, and picked up the idea of laser fusion produced by laser heating. Siegel cannibalized 42 companies to satisfy resources for his new KMS Fusion company. Later when testifying before a government committee, he had a crisis (heart attack, he says) and soon died. The company KMS Fusion survived on his life insurance for about a year.

Siebert had worked on the laser fusion project. His oscillator had been designed to produce mode-locked pulses from a French laser system and GE amplifiers. The shortest pulse, Qswitched, was about 3 nS (?) — too long. So Siebert developed a Y AG laser — silica glass — and designed a mode-locked laser with a flowing dye cell, giving 30 pS pulses. And they made the first neutrons with that Ann Arbor on South Industrial highway in Ann Arbor.

Sandy Thomas knew that Siebert was available to join the KMS Industries team.

KMS Fusion was a higher profile job than Conductron. More papers came out from KMS Fusion. Siebert never read too much of the holography papers — it was for the marketing group — so reading them now strikes him as surprising.

Conductron really sold McDonnell Missouri on holography — they spent a fortune moving all the equipment down. They thought initially some 16 people would go down, but in fact only a couple moved down. The pulsed laser was gotten up and running, and he helped to teach a few people down there how to use it, but it wasn't an effective teaching session. Most people stayed in Ann Arbor.

A friend at Conductron was divorced "too" — like Siebert? [Showed a Conductron newsletter with Siebert receiving an award.]

David Ainsley was his boss after KMS Industries decimated Conductron. Bob Buzzard had left and Ainsley took over. A young fellow with an MS in optics, who took over the optics department. Did he know Stroke? 'not real well, but a few people there were familiar with him' chuckles — 'Stroke had a reputation for being one of those bosses that would essentially publish all your work' Almost all the pulsed holograms of that period were made by him and his laser. At one time they were trying to produce wall display reflection holograms. Going through collection of papers.

Conductron sold a few of the oscillators he had developed. People weren't using anything but ruby, and the ruby rods weren't that good, so it wasn't simple to put together and make it work. Couldn't sell them as a kit; they sold them as complete laser systems made from commercial components.

The big thing was to get contracts for holograms themselves. If it hadn't been for a downturn of the economy, they had a deal with Ford to made holograms of cars to avoid having to have real vehicles transported to shows — a $700K contract bid.

He was full time working on holography at Conductron. He had obtained security clearance at North American, but he wasn't involved in the radar cross section R&D and Conductron. At KMS Fusion he got Q clearance — "they took your references and went out and talked to them". They couldn't even talk about certain words regarding the project -little cylinders with holes at ends to have laser beam enter used by others, but at KMS Fusion a 4 pi illumination of the pellets.

Some Conductron annual reports had pictures of Siebert and his laser system.

April 1970 Applied Optics 'Techniques for pulsed laser holography of people' the tail end of his job at Conductron. [Proc IEEE 60 No.6 (1972) p.655 — survey article by Gabor.]

Where are those old holograms now? McDonnell Douglas went through them, and the good ones went to Missouri. Siebert kept a handful for himself- he made a couple of the holograms of himself, on a glass 4x5" slide. He is prouder of a paper that has a lot of high-powered mathematics than the experimental production of the first pulsed-portrait. Proud too of his mode-locked laser system for KMS Fusion. Still working as a consultant on laser systems. [Holosphere 1987 — article on Conductron and McDonnell Douglas.] He doesn't know Hans Bjelkhagen. He used to go to CLEO meetings, and see holograms there.

Poker table hologram — some of the guys at Conductron. One was the old fellow in the optical coating department. One of the marketers, too. Thinks it was an 18x24" plate. Had a photo diode to check intensities, and on smaller holograms would make a couple to find mistakes, but that one was a one-off. 'You didn't want to waste many of those big plates.' That one, and most other ideas, were defined by the marketing people. An artist came in — "making pictures of him with funny faces" (Bruce Nauman) — he didn't know what the financial deal was, but he made the holograms. He was there for about a day or so. Not a lot of outside people came — made pop or beer can holograms for HNDT tests.

Bob Wolfe — now treasurer of Optical Society —

Siebert has a disabled brother and does the farming in Ohio for him. Siebert consults in Ann Arbor; designing 15 different electronics boards for a new laser system. 'Not flipping hamburgers' — a continuity from the 1960s.