Dennis Gabor Dies at 78 Invented Holography

LONDON—Dennis Gabor, inventor of the principle of wavefront reconstruction, or holography, died February 8 here after a long illness. He was 78.

Generally considered to be the "father of holography, " Gabor began to develop his invention about three decades ago. Subsequently, hundreds of workers have advanced and developed holography, giving Gabor the distinction of being, as he stated in his acceptance speech for the 1971 Nobel Prize in Physics, "one of the few lucky physicists who could see an idea of theirs grow into a sizable chapter of physics. "

Holographic techniques are now routinely used in industrial testing, are the subject of research for medical imaging and optical computing systems, offer scientists a valuable microscopic tool and provide a means for controlling and directing light in optical systems. In addition, holography has captured the public imagination as a method of displaying three dimensional images. As an art medium it continues to attract new artists and viewers each year.

Gabor conceived of holography in 1947, not while working in the lab, but while waiting for a tennis court in Rugby, England. It has been said watching the flight of tennis balls during his wait led to his idea, but Gabor said later, "I put the problem (of improving the electron microscope) into my own consciousness, and it came out of my unconsciousness when I was sitting" (New York Post Nov. 6 1971).

Gabor also stressed the nature of his idea, describing it as an invention, not a discovery. At a press conference in 1971, after being notified of winning the prize, Gabor said, '1 feel that I am very, very lucky. Most people get the prize for the one thing they spend a long life in science m accomplish I am an outsider. I've worked in industrial laboratories most of my life, and industrial workers rarely act Nobel Prizes. What I did was not pure science. I consider it an invention" (New York Times Nov. 3, 1971)

Born June 5, 1900 in Budapest Hungary, he may well have become initially interested in invention through his father, Bertalan Gabor, the director of the Hungarian General Coal Mining Company. The elder Gabor told him about the careers of such men as Thomas Edison. Later in life, Gabor said he could still remember the excitement he felt on his first trip to the Museum of Technology, Budapest at 13.

In 1918, after a brief career in the Hungarian artillery, Gabor enrolled in the Technical University in Budapest. In 1921, he entered the Technische Hochschule, Berlin, receiving a diploma in electrical engineering in 1924. He received a doctorate in that field from the school in 1927 for his thesis on the development of a high-speed cathode-ray oscillograph for recording microsecond phenomena.

He entered the industrial world through the German firm Siemens Halske, a Berlin electrical company, shortly after receiving his doctorate. While there he concentrated on the study of gas discharges and invented a molybdenum ribbon-seal in quartz.

In 1933, however, Gabor fled Germany to escape the rise of Nazism. I he returned briefly to Hungary anti then moved on to England. There, after initial unemployment, Gabor attracted the interest of the Thomson-Huston Company of Rugby, through one of his inventions—a plasma lamp. Thomson-Huston overcame government regulations concerning Gabor so lack of a work permit and hired him as a research engineer During this time, Gabor invented holography. Imagemaking had been a long-standing interest of Gabor's. As a teenager, he had wondered about the possibility of seeing through frosted glass, and he kept his fascination about the nature of photographic images and light into his career. At Thomson-Huston, Gabor explored these topics within the context of his research.

In his Nobel acceptance speech, Gabor explained that in 1947 he had been thinking about a method to improve the practical resolution of the electron microscope, which fell short of the theoretical resolution limit. After pondering this problem for a long time a solution suddenly dawned on me . . . Why not take a bad electron picture, but one which contains the whole information, and correct it by optical means? It was clear to me for some time that this could be done, if at all, only with coherent electron beams, with electron waves which have a definite phase. But an ordinary photograph loses the phase completely, it records only the intensities. No wonder we lose the phase, if there is nothing to compare it with! Let us see what happens if we add a standard to it, a 'coherent background".

A "little mathematics" proved the principle was right, Gabor said. He pointed out the relationship of his investigations to those of W. Lawrence Bragg in x-ray microscopy, and Frits Zernike in lens aberration studies using a coherent background. "It was only the reconstruction principle which had escaped them,'' he said.

That the invention came about through research into electron microscopy was fortunate, he said, for if his idea had come to him purely in the context of optics, Thomson-Huston, an electrical engineering concern, might not have permitted the research. But a related company, Metropolitan Vickers, manufactured electron microscopes, and Gabor obtained permission to conduct optical experiments. In 1948, working with filtered light from a mercury-arc lamp, Gabor and Ivor Williams, an assistant, made the first hologram, a term Gabor coined, from a transparency containing the names of three Optical scientists: Huygens, Young and Fresnel.

Moving on in 1949 to the Imperial College of Science and Technology of the University of London, Gabor continued in his efforts to employ holograms in electron microscopy. He worked as a consultant with a group at the research laboratory of the Associated Electrical Industries. After three years of work, we succeeded in considerably improving the electron microscope but in the end we had to give up, because we had started too early " Twenty years later, he noted, the defects of the microscope had been overcome, giving him hope that an electron microscope might ultimately resolve atomic lattices, ''the realization of my old ideas. "

Although holography proved unsuitable for electron microscopy, Gabor's publications on wavefront reconstruction published from 1948-1949. the most famous being ''Microscopy by Reconstructed Wavefronts Proc Roy. Soc. (London) AI97, 457-4X7, 1949 evoked sonic immediate responses from G. L, Rogers, Albert Baez, Paul Kirkpatrick and Hussein El-Sum. Still, in their work they shared with Gabor the limitations of incoherent light sources ''Around 1955 holography went into a long hibernation." according to Gabor

Holography reemerged suddenly and explosively in 1963 with the publication of the first successful laser holograms by Emmett Leith and Juris Upatnieks. Gabor had not known of Leith's research beginning in 1955 into side-looking radar, described by Gabor as "two-dimensional holography with electromagnetic waves," because the work was classified, nor, as Leith has pointed out, was he aware of Gabor's work.

The existence of a coherent light source and the v work of Leith and Upatnieks brought many workers into the field of holography, and the significance of the principle grew considerably In recognition of this, Gabor received the Nobel Prize, 23 years after his invention.

During his association with Imperial College, where he ultimately became professor emeritus of applied electronic physics, Gabor also worked from the early 1950's to the mid-1970's as a research engineer and lifetime consultant for CBS Laboratories, now known as the CBS Tech nology Center. He came to the organization at the invitation of Peter Goldmark, founder of CBS Laboratories. The two had been friends for many years; Goldmark had been one of Gabor's laboratory assistants at the Technische Hochschule.

Renville McMann, president of Thomson CSI. was vice president of engineering at CBS Laboratories from 1971 to 1976. In a recent interview he described Gabor's invention of holography as an "amazing accomplishment," adding, "Gabor went past the ray-tracing diagrams of the time and analyzed what was actually going on in an optical image."

"As one reflects back on his genius,'' McCann continued, "one recalls his work in information theory in the 1930's, a field he helped to define. Another interesting instance was the development of the Schmidt telescope, which is actually a special case of the Gabor telescope. He was a prolific man."

Gabor's interest in holography extended beyond its scientific applications, He described holographic motion pictures and holographic art as "two of my favorite holographic brainchildren." He discussed the use of a holographic screen to display three-dimensional images in the 1960's, pointing out his interest in this area began before holography. He also suggested a technique of " panoramic holography for displaying scenes in full size. His attraction to the art of holography was also indicated by his support of the Museum of Holography of which he became honorary chairman of the hoard of trustees in 1979.

Another somewhat lesser known, aspect of his career was his interest in futurism. In three books Inventing the Future, Secker and Warburg, 1963, Knopf, 1964; Innovations, scientific Technological and Social, Oxford University Press, 1970 and The Mature Society Secker anti Warburg, 1979 Praeger, 1972) he provides a sobering vision of the future in which the issues of overpopulation, nuclear weaponry and an excess of mass leisure conspire to produce social upheaval and world anxiety. To solve future problems, Gabor suggests in Innovations that society must, among other things, redefine its notion of progress:

"The time of simple solutions is long behind us, though we are still suffering from the simplistic slogans of the nineteenth century, such as 'Free Enterprise' or 'Common Ownership of the Means of Production. We have long ago entered the era of compromises, of the piecemeal reconcilement of human nature and of vested interests with desirable aims, national and international. The struggle with these contrary forces has recently visibly shortened the 'lead times,' and we can see the governments planning for months ahead, rather than for ten to twenty or snore years.

"If this goes on much longer. we are certain to run into a catastrophe, even without an all-out nuclear war. With the present trend, the world population will double by the year 2000—and A.D. 2000 ought not to be the end of the world. Unfortunately, all our drive and optimism are bound up with continuous growth; 'growth addiction is the unwritten and unconfessed religion of our times. In industry and also for nations, growth has become synonymous with hope. Undoubtedly, quantitative growth will have to go on for many more years, but unless we prepare for a turning point well before the end of the century, it may then be too late."

During his career Gabor received more than 100 patents. They include proposals for holographic television and numerous other holographic applications.

Gabor also received numerous awards. Among them are: fellow of the Royal Society, honorary member of the Hungarian Academy of Sciences the Thomas Young Medal and Prize of the Physical Society, the Cristoforo Colombo Prize of Genoa, the Rumford Medal of the Royal Society, the Medal of Honor of the Institute of Electrical and Electronics Engineers, the Semmelweiss Medal of the America Hungarian Medical Association, and the CBE (Commander of the British Empire).

While at Rugby in 1936, Gabor married Marjorie Louise Butler. The couple had no children. He is survived by her and a brother, Andre.Gabor was a naturalized British subject.

References: Current Biography, 1972, pp. 168170 and Le Prix Nobel en 1971, 1972, the Nobel Foundation, pp. 169-201.