Dennis Gabor – the inventor of holography By Andrei Nesterovitch Stephen F. Austin State University BIO 575 Instructor – Dr. Alexandra Van Kley Fall 2003

WHAT IS HOLOGRAPHY? Encyclopedia Britannica: Date: 1964 : the art or process of making or using a hologram

WHAT IS HOLOGRAM? Encyclopedia Britannica: Date: 1949 : a three-dimensional image reproduced from a pattern of interference produced by a split coherent beam of radiation (as a laser); also : the pattern of interference itself

Although often compared with photography, holography is really a completely different medium. Traditional Pictures Have No 'Depth‘ When we look at a photograph and move it from side to side, we are unable to see ‘around' the scene or perceive any depth. Likewise, we cannot see over or under the image. Multiple Views Create '3D Effect' A hologram is also flat, but the image captured by the hologram is not. When we look at a hologram and move it from side to side, we can see many different views of the scene. We can also look behind foreground elements to see things in the background. WHAT IS HOLOGRAPHY?

Holograms Appear to 'Leap Off' the Film Another difference between holograms and photographs is that holographers can position their images to ‘project off' or ‘float over' the surface of the film. A viewer can reach out and put his hand right through the apparently solid image. WHAT IS HOLOGRAPHY?

The biography of Dennis Gabor ( ) "You can't predict the future, but you can invent it." - Dennis Gabor D. Gabor was born in Budapest, Hungary, and his life-long love of physics started suddenly at the age of 15. He learned the calculus and worked through the textbook in the next two years. With his late brother George, they also built up a little laboratory in their home, where they could repeat most experiments which were modern at that time, such as wireless X-rays and radioactivity.

The biography of Dennis Gabor He acquired his degrees in electrical engineering in High Technical School, Berlin (Diploma in 1924, Dr-Ing. in 1927). Though electrical engineering remained his profession, his work was almost always in applied physics. His doctorate work was the development of one of the first high speed cathode ray oscillographs. In 1927 D. Gabor joined the Siemens & Halske AG where he made his first successful inventions; the high pressure quartz mercury lamp with superheated vapor and the molybdenum tape seal, since used in millions of street lamps. In 1933, when Hitler came to power, Gabor left Germany and after a short period in Hungary went to England, where obtained employment with the British Thomson-Houston Co., Rugby.

The biography of Dennis Gabor The years after the war were the most fruitful. He wrote, among many others, his first papers on communication theory, developed a system of stereoscopic cinematography, and in 1948 carried out the basic experiments in holography, at that time called "wavefront reconstruction". Then, until his retirement in 1967, he improved Wilson chamber, developed holographic microscope, a new electron-velocity spectroscope, flat thin color television tube. Theoretical work included communication theory, plasma theory, magnetron theory.

The biography of Dennis Gabor In 1971 Dr. Dennis Gabor was awarded the Nobel Prize in Physics for his discovery of holography in But, in his own words – “We had started 20 years too early. Only in recent years have certain auxiliary techniques developed to the point when electron holography could become a success. On the other hand, optical holography has become a world success after the invention and introduction of the laser”.

The history of holography Gabor coined the term hologram from the Greek words holos, meaning "whole," and gramma, meaning "message". The term holography is from Greek words holos and grapho – “write”, that means complete record of the image. Gabor's holography was limited to film transparencies using a mercury arc lamp as the light source. His holograms contained distortions and an extraneous twin image. Further development in the field was stymied during the next decade because light sources available at the time were not truly "coherent" (monochromatic or one-color, from a single point, and of a single wavelength).

The history of holography This barrier was overcome in 1960 with the invention of the laser, whose pure, intense light was ideal for making holograms. Laser (light amplification by stimulated emission of radiation) was invented by Nikolai Bassov, Alexander Prokhorov and Charles Townes (all became in 1964 Noble Prize winners). Nikolai BassovAlexander ProkhorovCharles Townes

The history of holography In 1962 Emmett Leith and Juris Upatnieks of the University of Michigan recognized from their work in side-reading radar that holography could be used as a 3- D visual medium. In 1962 they read Gabor's paper and "simply out of curiosity" decided to duplicate Gabor's technique using the laser and an “off-axis technique” borrowed from their work in the development of side- reading radar. The result was the first laser transmission hologram of 3-D objects (a toy train and bird).

The history of holography Also in 1962 Dr. Yuri Denisyuk combined holography with 1908 Nobel Laureate Gabriel Lippmann's work in natural color photography. Denisyuk's approach produced a white-light reflection hologram which, for the first time, could be viewed in light from an ordinary incandescent light bulb. Russian scientist Yuri N. Denisyuk, State Optical Institute in Leningrad, USSR, signing a copy of his book, Fundamentals of Holography. (Photo by Dr. Stephen Benton, 1979)

The history of holography In 1967, Larry Siebert of the Conductron Corporation used a pulsed laser that he designed to make the first hologram of a person. The Conductron Corporation (later acquired by McDonnell Douglas Electronics Corporation) played an important role in the early days of commercial display holography.

The history of holography A major advance in display holography occurred in 1968 when Dr. Stephen A. Benton invented white- light transmission holography while researching holographic television at Polaroid Research Laboratories. This type of hologram can be viewed in ordinary white light creating a "rainbow" image from the seven colors which make up white light.

The history of holography In 1972 Lloyd Cross developed the integral hologram by combining white-light transmission holography with conventional cinematography to produce moving 3- dimensional images. Sequential frames of 2-D motion-picture footage of a rotating subject are recorded on holographic film. When viewed, the composite images are synthesized by the human brain as a 3-D image. Later, Cross founded The Multiplex Company that produced hundreds of images using his holographic stereogram technique.

The history of holography From , Rich Rallison (International Dichromate Corp., Draper, UT) pioneered the production of glass sandwich dichromate holograms that were used as jewelry pendants, key chains, paper weights, and other premium items. Rich Rallison recalls his experiences with Steve Benton at the Benton Vision Symposium, November, 2003.

The history of holography In 1983 MasterCard International, Inc. became the first to use hologram technology in bank card security.

Holography application A telephone credit card used in Europe has embossed surface holograms which carry a monetary value. When the card is inserted into the telephone, a card reader discerns the amount due and deducts (erases) the appropriate amount to cover the cost of the call. Supermarket scanners read the bar codes on merchandise for the store's computer by using a holographic lens system to direct laser light onto the product labels during checkout. Holography is used to depict the shock wave made by air foils to locate the areas of highest stress. These holograms are used to improve the design of aircraft wings and turbine blades.

Holography application A holographic lens is used in an aircraft "heads-up display" to allow a fighter pilot to see critical cockpit instruments while looking straight ahead through the windscreen. Similar systems are being researched by several automobile manufactures. Researchers are developing the sub- systems of a computerized holographic display. Holography is ideal for archival recording of valuables or fragile museum artifacts. Optical computers, which use holograms as storage material for data, could have a dramatic impact on the overall holography market.

Holography application To better understand marine phytoplankton, researchers have developed an undersea holographic camera that generates in-line and off-axis holograms of the organisms. A computer controlled stage moves either a video camera or a microscope through the images, and the organisms can be measured as they were in their undersea environment An interferogram (a sort of hologram) is a technique providing a method of non-destructive analysis that determines structural deformations in objects.

Holography application The using of ultrasound waves as main carriers of the information creates opportunities for holography application in a sound field visualization. This has a great practical importance in: - Undersea acoustics and hydrolocation; - Defectoscopy; - Medical diagnostics; - Biological surveys The using of X-rays as main carriers of information creates additional opportunities for holography method application in biological, physical and chemical studies

Holography application The using of γ –rays allows precise atomic and molecular structural analysis: (a)Holograms of a local structure of crystallic Fe (b) Estimated pictures of a local structure of crystallic Fe

Thank you! SOURCES: