SCIENTISTS

Stephen Benton :

 Pioneer of modern holography 

Stephen Benton (1941-2003) as well, is amongst the pioneers of modern holography. He is the inventor of Benton holography, also referred to as rainbow holography (1969), a fascinating holographic process that allowed the subsequent realization of holograms that can be illuminated with white light, holograms that display in true colours, and holograms that display true color cinematographic animations. The May 2004 issue of the magazine "Holography" features a tribute to Stephen Benton as a scientist, a teacher, a colleague and a friend.

Download: Steve Benton.pdf

SCIENTISTS

Yuri Denisyuk :

 Pioneer of modern holography

The eminent Russian gentleman and physicist Yuri Denisyuk (1927-2006) together with Emmett Leith (1927-2005) and Juris Upatnieks (b. 1936) must be honoured as one of the pioneers of modern holography. After lasers became available Denisyuk developed "volume reflection holography" rightfully also called "Denisyuk holography".
Denisyuk began experiments in interference photography in 1958 and published his work in 1962 in the Soviet Union. But his research was not well received until the work of Leith and Upatnieks began to generate excitement in the late sixties. In 1970 he was awarded the Lenin Prize and was elected a member of the Soviet Academy of Sciences. Denisyuk and Leith received the first Dennis Gabor Award from SPIE in 1983.

SCIENTISTS

Emmett Leith:- 

 Pioneer of Modern Holography

As early as 1956, Emmett Leith of the University of Michigan reinvented holography as a spin-off of his research on side-reading radar. Only in the early 1960s, after the invention of the laser, the first off-axis laser transmission holograms were recorded by Leith and his colleague Juris Upatnieks. These novel holograms of diffusely reflecting objects produced stunning three-dimensional and full-parallax reconstructions of the original object. The impact of this invention on the careers of many can hardly be overrated.

SCIENTISTS

Gabriel Lippmann : 

Pioneer in photography 

Gabriel Lippmann (1845-1921) developed a method of capturing coloured images in black-and-white photographic emulsions. His stunning invention, now called Lippmann colour photography, was based on the phenomenon of light interference in thin films. In hindsight, it is straightout unbelievable that this advanced photographic process was developed as early as 1891, after years of patient experiments.
His invention gained Lippmann the Nobel prize for Physics in 1908.
Lippmann's invention was the precursor of Yuri Denisyuk's volume reflection holography. See chapter 7 of Optical Document Security, 3rd edition.

Download: Lippmann.pps

SCIENTISTS

Willebrordus Snellius -

 Refraction of light ©

Willebrord Snel van Roijen (1580-1626) was a distinguished Dutch mathematician, physicist and astronomer. He used the latin name "Willebrordus Snellius" as his scientific alias. Snel (written with one l) is most famous for his discovery in 1621 of the law of refraction, generally referred to as "Snel's law".
Phenomena such as "the broken stick", focusing of light by a lens, imaging by a lens, prismatic colours and the rainbow are all based on the refraction of light when it passes from one medium to another, provided that the optical density of both media is different.
The downloadable slideseries (3.7 Mb) shows that the refractive index of various security features defines their optical behaviour. (slideseries expanded per 21 July 2007).

Download: Refraction.pps

NOBEL LAUREATES

Dennis Gabor
Born	5 June 1900 Budapest, Hungary
Died	9 February 1979 (aged 78) London, England
Citizenship	British / Hungarian
Fields	Electrical engineering
Institutions	Imperial College London British Thomson-Houston
Alma mater	Technical University of Berlin Technical University of Budapest
Known for	Invention of holography
Notable awards	Nobel Prize in Physics (1971) IEEE Medal of Honor (1970)

BRIEF LIFE SKETCH

He was born as Gábor Dénes,^[2] into a Jewish family in Budapest, Hungary.^[3] He served with the Hungarian artillery in northern Italy during World War I.^[3] He studied at theTechnical University of Budapest from 1918, later in Germany, at the Charlottenburg Technical University in Berlin, now known as the Technical University of Berlin.^[2] At the start of his career, he analyzed the properties of high voltage electric transmission lines by using cathode-beam oscillographs, which led to his interest in electron optics.^[2] Studying the fundamental processes of the oscillograph, Gabor was led to other electron-beam devices such as electron microscopes and TV tubes. He eventually wrote his Ph.D. thesis concerning the cathode ray tube in 1927, and worked on plasma lamps.^[2]

As a Jew, Gabor fled from Nazi Germany in 1933, and was invited to Britain to work at the development department of the British Thomson-Houston company in Rugby, Warwickshire. During his time in Rugby, he met Marjorie Butler, and they married in 1936. He became aBritish citizen in 1946,^[4] and it was while working at British Thomson-Houston that he invented holography, in 1947.^[5] He experimented with a heavily filtered mercury arc light source. ^[2] However, the earliest hologram was only realized in 1964 following the 1960 invention of the laser, the first coherent light source. After this, holography became commercially available.

Gabor's research focused on electron inputs and outputs, which led him to the invention ofre-holography.^[2] The basic idea was that for perfect optical imaging, the total of all the information has to be used; not only the amplitude, as in usual optical imaging, but also the phase. In this manner a complete holo-spatial picture can be obtained.^[2] Gabor published his theories of re-holography in a series of papers between 1946 and 1951.^[2]

Gabor also researched how human beings communicate and hear; the result of his investigations was the theory of granular synthesis, although Greek composer Iannis Xenakis claimed that he was actually the first inventor of this synthesis technique.^[6]

In 1948 Gabor moved from Rugby to Imperial College London, and in 1958 became professor of Applied Physics until his retirement in 1967. While spending much of his retirement in Italy, he remained connected with Imperial College as a Senior Research Fellow and also became Staff Scientist of CBS Laboratories, in Stamford, Connecticut; there, he collaborated with his life-long friend, CBS Labs' president Dr. Peter C. Goldmark in many new schemes of communication and display. One of Imperial College's new halls of residence in Prince's Gardens, Knightsbridge is named Gabor Hall in honour of Gabor's contribution to Imperial College. He developed an interest in social analysis and publishedThe Mature Society: a view of the future in 1972.

Following the rapid development of lasers and a wide variety of holographic applications (e.g. art, information storage, recognition of patterns), Gabor achieved acknowledged success and worldwide attention during his lifetime.^[2] He received numerous awards beside the Nobel Prize.

  Download: Gabor's experiment repeated.pps

NOTABLE AWARDS

• 1956 - Fellow of the Royal Society
• 1964 - Honorary Member of the Hungarian Academy of Sciences
• 1964 - D.Sc., University of London
• 1967 - Young Medal and Prize, for distinguished research in the field of optics
• 1967 - Colombus Award of the International Institute for Communications, Genoa
• 1968 - Albert Michelson Medal of The Franklin Institute, Philadelphia
• 1968 - Rumford Medal of the Royal Society
• 1970 - Honorary Doctorate, University of Southampton
• 1970 - Medal of Honor of the Institute of Electrical and Electronics Engineers
• 1970 - Commander of the Order of the British Empire (CBE)
• 1971 - Nobel Prize in Physics, for his invention and development of the holographic method