Robert Haun

It was while I was in process of being hired by Westinghouse, but was still at MIT, that I became interested in optical pumping. Some staff members at Westinghouse’s R&D Center had heard about Bloembergen’s work with optical pumping of ions in solids, so sometime in mid-1956, I went over to Harvard and talked with Pipkin, who was working for Bloembergen I came to the R&D Center in February 1957.

I was in a magnetic resonance section, looking at ferrites. We had a little discussion group on magnetic resonance of ions in crystalline materials at the time Ohlmann was one member, another was Asendorf, who formed a bridge between our group and Wielder’s and knew of Wielder’s interest in masers. Optical pumping was pertinent to our interests, as were nonlinear devices and phase shift effects. While Wieder had proceeded with experiments and tried to optically pump ruby, my group focused on optical spectroscopy and magnetic resonance for microwave devices until Maiman’s “breakthrough.” We had been expressing interest in optical pumping but the manager of our department, which was more applied than Wielder’s, did not choose at that time to devote his discretionary funds to lasers. After Maiman made the ruby laser, he became more interested and Westinghouse decided it ought to do something with lasers. In a few weeks, Bob Ohlmann, Ted Osial and I constructed one with the best pale ruby we could buy commercially.

We also gave a talk on a theoretical topic, laser oscillators as super regenerative amplifiers, at the March 1961 meeting of the Optical Society of America. The next significant thing happened when I was asked to head a study group with people from a number of divisions, mostly Defense divisions, to decide what it would take to use lasers in missiles. Our Defense divisions had probably previously been aware of the classified program at TRG, but the Maiman demonstration created new funding opportunities in DOD which provided the incentive for this activity to be initiated in Westinghouse.

The study group included lamp experts, electronics experts, defense systems experts, and theoretical physicists among others. The commercial lamp division in Bloomfield, New Jersey sent one person; this division made flash lamps for airport landings. The high power microwave tube division in Elmira was another commercial division which had a representative. These contacts on the task force ultimately led to our involvement with those divisions in both commercial and military laser systems. We spent alternate weeks in Pittsburgh and Baltimore, working on conceptual designs. This was a company funded study. We concluded it was too demanding with ruby; about one cubic city block of ruby and flash lamps would be needed. We took the stance, however, that it did not appear impossible, although we faced a lot of sarcastic comments about missile melting from our peers within the Research Laboratory.

It was after this study that I began to learn of Department of Defense interests, and our Defense Division took me along on various presentations which we made to ARPA and others. The Defense Division was not as well established then as it is now. It specialized in torpedoes and radar and represented about 5% of Westinghouse business. The DOD was beginning to set up programs on the basis that it might be conceivable to have weapons, programs looking at problems like multiple beams. The Defense Division got a contract for a phased assembly of solid-state lasers (ruby initially) for a couple of million dollars, a big contract for those days. In pursuit of this contract, the Division asked us to look at materials with better properties. There were two activities. The Air Arm Division, which made airborne radars, wanted us to look for more efficient solid-state lasers’ for them. The Baltimore Surface Division, which made ship borne radars for the Navy got interested in high power lasers for missile melting.” Our resources at the Research Laboratory were such that we could better handle the small-power work, and we aimed our long-range strategy at that, but our Defense divisions tended to fund high-power thrusts, as did the DOD, so much of our work was aimed toward the high power end too. One of the high power projects was an Army Missile Command contract on big flash lamps. Chuck Church, who had been recently hired (he subsequently went to the Pentagon as science planner for the Army) worked on that, and his work formed a bridge for us with the lamp division. Through the Army Missile Command we got ND: glass samples from American Optical, to use in testing our flash lamps.

We also involved the Lamp Division in a contract with John Creeden of Fort Monmouth, hydrogen thyratron radar-pulsar man who moved into the area of pulsed flash lamps. It was this thrust that pointed us to commercial applications. We evolved a flash lamp which had a unique geometry which gave high efficiencies in small pulsed ND: glass lasers. We submitted it to Industrial Research for their annual contest for the 100 best inventions. No Division had expressed a desire to manufacture it, and processes for transferring inventions to the divisions were then not well worked out. We wanted to see whether the outside world was interested. If we got orders from outside, we figured we’d find some way to satisfy them and if there were enough orders, this would make the product acceptable to the divisions.

We knew our design was novel, and better than others. Management didn’t encourage entrepreneurship of this sort. The philosophy was that if you do good R&D, someone in the divisions would pick it up. But in fact, it wasn’t that easy. We did get an Industrial Research award and a few inquiries. A few people wanted to buy our reflector, but that was all The Defense Division got interested, but the size of our geometry was large for their airborne applications. We almost got the interest of the electronics division, but they didn’t see much market for it, while we ourselves didn’t know much about markets. We were just learning then to market contracts to the DOD, first through the Defense Division and then directly.

About that time, the Defense Division doubled the money they sent to the R&D Center for lasers. The group had now grown to a department of 4 people for growing crystals, a group of 3 for spectroscopy of materials, 2 working on laser glasses that could compete with American Optical, 1 on liquid lasers, 1 on gas lasers, 1 on nonlinear modulators, and 2, (Ted Osial and Ken Steinbrugge), investigating industrial applications. I was department manager by this point, and by about 1966, we numbered about 60 people counting technicians. About 70% of this activity was funded by Westinghouse and the rest by DOD, either through the Division or by contracts. There now arose a general feeling in this group that the activity was getting large and was all military.

Why not get civilian applications in on it? Although the Defense Division funded us, lasers were not receiving high priority within the Defense Division. We saw a new technology growing throughout the world, with great potential, and we at the R&D Center were continually frustrated over the lack of management interest. Then on February 14, 1966, the Defense Division lost interest. Our group had to be reduced by 40-50% overnight. The Defense Divisions were reading the tea leaves that the government was losing interest. There was growing disenchantment with the technology. The average power of glass and ruby lasers was limited. Gas lasers, if they flowed, flowed longitudinally, which was not enough of an improvement. From a peak of 60 the staff ultimately went as low as 25, and didn’t return to its early levels until 1971-72. Our group championed a number of laser products with varying success. We had earlier tried to convince the electronic tube division to build helium-neon lasers, since these would have fit in with their technology, but the division didn’t see sufficient volume of sales.

We wrote several papers in 1963-1966 on the applications potential of lasers. In demonstration experiments, we used ruby and ND: glass for spot welding. I recall I published a paper in the IEEE Spectrum discussing the potential use of lasers for monitoring currents, for surgical applications, in mensuration, and for defining straight lines. Few of those applications were in commercial use at that time. One dramatic incident occurred when the electronics tube division performed a shake test on some expensive imaging tubes and found that the welds, which were already encased in glass, were faulty. Osial demonstrated that he could repair the welds on 2 samples, and they shipped us the others. They saved $2-3,000 per tube, or $20,000 per tube, were they to have rebuilt them from scratch.

About that time, the Scientific Equipment Division was set up, with one department specifically tasked to pursue electro-optics imaging devices and lasers. These systems were based upon our application group’s work. They sold ruby laser systems for punching holes in wire-drawing dies. Many years after I thought it possible, one company in Indiana was still using one of these systems, which had been sold in about 1967. That division eventually folded and laser applications were transferred to the Sykesville Industrial Equipment Division, which was also marketing an out-of-vacuum electron-beam welder. We also worked on CO₂ lasers. Bud Weaver, a University of Illinois graduate, had been working on large, longitudinally flowed CO₂ lasers in one of my groups, studying scaling limitations, and effects of varying the diameter, and looking at applications. Then I went to a meeting in Pensacola, Florida, in 1967. There I heard AVCO present their gas dynamic CO₂ laser which used transfer flow to enable 10’s of kilowatts of average power output. A breakthrough!

At about this same time the current-interruption technology group in the Research Laboratories conceived and demonstrated what has subsequently been named the UV-initiated CO₂ laser. Dave Hundstad became the sparkplug in this CO₂ work with Wutzke as his co-worker, within the next year or so they reported to me The initial UV initiated laser did not have flowing gas and Hundstad and Wutzke lacked the security clearances necessary to be told of the AVCO breakthrough, but they set up a small transverse-flow test of their concept very soon after I learned of it. Within a few years they had developed a large, closed-loop ultra-violet excited CW laser with maximum continuous output powers of 8 kwatts. We never convinced the Industrial Equipment Division, however, of its usefulness as a low cost, industrial unit. They were also skeptical about its reliability although it continued to operate in our laboratory for many years after with very little maintenance. In addition, Sykesville was getting into some financial problems at this point, because their out-of-vacuum electron beam welder was not panning out. Our first transverse flow continuous CO₂ laser operated in 1972 and we carried research on until 1979-1980 but never translated it into a commercial product.

We tried to interest the Army but they lost interest because extremely high powers were not achieved. In terms of military contracts, many years passed until finally we prevailed against AVCO in developing intermediate power pulsed lasers for the Army Missile Command. Development of pulsed versions of transverse-flow UV-initiated CO₂ lasers continued into the mid-1980s. We never went into gas dynamic lasers experimentally. We were primarily an electrical equipment company and since it derived its energy from combustion, without any electrical involvement, it didn’t fit with anything Westinghouse did. We did work with our Astronuclear Laboratory for a couple of years to develop and market a preliminary concept for use of a nuclear reactor to heat the gases for a multimegawatt CO₂ gas-dynamic laser, but that way dropped when the chemical HF lasers were shown to have much higher efficiency and lighter weight at comparable power levels. Westinghouse did a study, eventuating in a strategy paper, with the thought that lasers with powers up to 10-100 kw might fit industrial needs.

In the end, our most significant commercial area was nonlinear optical materials. This work, done by Jack Feichtner and Bob Mazelsky, led to a number of materials, of which the thallium arsenic selenide chalchogenide compounds are an example, for acousto-optic applications, some of which operate over very wide wavelength ranges. One of the products using these materials is an electronically-driven spectrometer with a “grating spacing” determined by the acoustic wavelength, for spectroscopy and other applications.