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Ali Javan

Ali Javan
Born(1926-12-26)December 26, 1926
Tehran, Iran
DiedSeptember 12, 2016(2016-09-12) (aged 89)
Los Angeles, California, U.S.
NationalityIranian
Alma materColumbia University
University of Tehran
Known forGas lasers
Lasing without inversion
Laser spectroscopy
Timing frequency of light
AwardsStuart Ballantine Medal (1962)
Albert Einstein World Award of Science (1993)
Scientific career
FieldsPhysicist
InstitutionsColumbia
Bell Labs
MIT
Doctoral advisorCharles Townes
Doctoral studentsMichael S. Feld[1]
Richard M. Osgood Jr.[1]
Irving P. Herman[1]
Other notable studentsTimothy Creamer[1]
Joseph J. Romm[1]

Ali Javan (Persian: علی جوان, romanized: Ali Javān); December 26, 1926 – September 12, 2016) was an Iranian American physicist and inventor. He was the first to propose the concept of the gas laser in 1959 at the Bell Telephone Laboratories. A successful prototype, constructed by him in collaboration with W. R. Bennett, Jr., and D. R. Herriott, was demonstrated in 1960. His other contributions to science have been in the fields of quantum physics and spectroscopy.[2]

Life and career

Ali Javan was born in Tehran to Azerbaijani parents from Tabriz.[3][4] He attended a school conducted by Zoroastrians.[5]: 43  He graduated from Alborz High School, and started his university studies at the School of Science at the University of Tehran for a year. During a visit to New York in 1948, he attended several graduate courses at Columbia University. He received his Ph.D. in 1954 under his thesis advisor Charles Townes without having received a bachelor's or master's degree.[5]: 44  In 1955, Javan held a position as a Post Doctoral in the Radiation Laboratory and worked with Townes on the atomic clock research, and used the microwave atom beam spectrometer to study the hyperfine structure of atoms like copper and thallium.

In 1957, he published a paper on the theory of a three-level maser,[6] and his discovery of the stimulated Raman effect showed that a Stokes-shifted Raman transition can produce amplification without requiring a population inversion.[7][8] The effect was the precursor of a class of effects known as Lasers Without Inversion, or the LWI effect.[9] He joined Bell Telephone Laboratories in 1958 shortly after he conceived the working principle of his gas discharge Helium Neon laser, and subsequently submitted his paper for publication which was reviewed by Samuel Goudsmit in 1960.[10][11]

Javan's gas laser was the first continuously operating laser. It operated with a very low energy input of about 25 watts[12]: 91  or 50 watts[13]: 58  in the first model, compared to thousands of watts required for the ruby lasers to produce short bursts.[12] The output laser power was ~ 1 milliwatt. In addition, the ruby laser is greatly surpassed in the narrowness of its output of wavelengths by the gas laser. Its beam of infrared light was slightly less than half an inch wide and spread no more than a foot over a distance of a mile.[12] Just one day after its realization, the laser was used to transmit a telephone call. Javan later described the moment: "I put in a call to the lab. One of the team members answered and asked me to hold the line for a moment. Then I heard a voice [Mr. Balik], somewhat quivering in transmission, telling me that it was the laser light speaking to me."[14]

In 1966, Ali Javan and Theodore Maiman split a cash award presented to them by President Johnson honoring their work.[15] In 1971, he became the director of Symposium on Laser Physics, which was held on the campus of University of Isfahan.[5]: 46 

Javan carried out the first demonstration of optical heterodyne beats with lasers in 1961.[16][17] Another major experiment was his observation of the detuning dip called the Lamb dip while scanning the frequency of a single-mode laser across the Doppler-broadened gain profile.[18] Ali Javan and his colleagues pioneered in stabilizing laser frequencies with techniques utilizing the Lamb dip.[19]: 740  In 1964, Javan and Townes devised experiments using lasers to test special relativity including a variant of the Michelson-Morley ether drift experiment to study the anisotropy of space.[20] Javan's group repeated the Michelson-Morley experiment with a new order of accuracy by turning their lasers in different directions with respect to the earth's motion. Any change in the velocity of light would show up as a change in the frequency of the output beam. The apparatus used was sensitive enough to detect a change as small as 0.03 millimeter per second (compared to the accuracy of 150 millimeters per second attained by Albert A. Michelson).[21]: 44 

At MIT in the early 1960s, Ali Javan started a research project aimed at extending microwave frequency-measuring techniques into the infrared. He introduced the concept of an optical antenna of several wavelengths long which enables the near-complete confinement of an incident optical field coupled to it, and forming the antenna in nanoscale. For the first time an antenna was used to receive light and to transmit it to an infinitesimal receiving structure at its tip, observable only with an electron microscope.[5]: 46  The antenna responded to infrared laser light and generated current vibrating at the frequencies of the incident beams. According to John L. Hall, during the 1962 American Physical Society meeting, Javan played a recording of the actual audio beat frequency between two of his lasers when they were tuned almost to the same optical frequency.[22] Using this method Javan developed the first absolutely accurate measurement of the speed of light.[23]

Javan first worked at Massachusetts Institute of Technology as an associate professor of physics in 1961 and has remained Francis Wright Davis Professor Emeritus of physics since 1964. He continued researching into the area of "optical electronics", which envisions scaling electronic elements in such a way that they would be capable of handling frequencies as high as visible optical radiation frequencies.[24]

Javan died on September 12, 2016. He is survived by his wife, Marjorie, and by their two daughters, Lila and Maia.[25]

Honors

In 2007, Javan was ranked Number 12 on The Daily Telegraph's list of the "Top 100 Living Geniuses".[29]

See also

References

Notes

  1. ^ a b c d e Javan, Ali. "MIT Dissertation and Thesis Advisees". MIT. Retrieved 30 October 2017.
  2. ^ Taylor, Nick (2000). LASER: The inventor, the Nobel laureate, and the thirty-year patent war. New York: Simon & Schuster. pp. 125–128. ISBN 978-0-684-83515-0.
  3. ^ "Ali Javan from Azerbaijan". www.edu-active.com. Retrieved 2023-09-01.
  4. ^ Ali Javan, scientist and inventor – obituary — Telegraph Archived 2017-11-14 at the Wayback Machine
  5. ^ a b c d Smithsonian April 1971 (Volume 2, Number 1), Ali Javan and his 40 lasers, Francis E. Wylie
  6. ^ Javan, A. Theory of a 3-Level Maser, Physical Review, 1957
  7. ^ Javan, A. Transitions a Plusieurs Quanta Et Amplification Maser Dans Les Systemes a Deux Niveaux, Journal De Physique Et Le Radium, 1958
  8. ^ Ali Javan interviewed by Jeff Hecht, on Feb 28, 1985. Lasers and Applications
  9. ^ MIT Web Page of Ali Javan. Biographical Sketch.
  10. ^ Interview with Ali Javan by Lee Sullivan at the Optical Society of America, Boston, Massachusetts (September 4, 2008)
  11. ^ Javan, Herriott and Bennett, Population Inversion and Continuous Optical Maser Oscillation in a Gas Discharge Containing a He-Ne Mixture, Physical Review Letters, 1961
  12. ^ a b c SCIENCE AND THE CITIZEN. (1961). Scientific American, 204(3), 80-93.
  13. ^ Schawlow, A. (1961). Optical Masers. Scientific American, 204(6), 52-61.
  14. ^ Javan, Ali with Blair, Betty. "Scientists Who Made A Difference:Ali Javan, The Gas Laser and Beyond", Azerbaijan International, Vol. 4:2 (Summer 1996), pp. 14-18
  15. ^ U.P.I. United Press International photo archives, 4/27/66
  16. ^ Interview with Ali Javan by Lee Sullivan at the Optical Society of America, Boston, Massachusetts (September 4, 2008) "[...]with Ed Ballik, the two of us saw the very first experiment done with lasers, a significant experiment showing the color purity of it, heterodyning them [two free running lasers]. The very first paper published by Optical Society is just that. [...]"
  17. ^ Javan, Ballik, Frequency Characteristics of a Continuous-Wave He-Ne Optical Maser, Journal of the Optical Society of America (1962)
  18. ^ Haken, Hermann. Laser Theory, Springer, 1984. pp. 199. ISBN 3540121889
  19. ^ Metz, W. (1972). Physics with Lasers: High Resolution Coming of Age. Science, 175(4023), 739-740.
  20. ^ Jaseja, Javan, Murray, Townes, Test of Special Relativity or of Isotropy of Space by Use of Infrared Masers, Physical Review a-General Physics (1964)
  21. ^ Schawlow, A. (1963). Advances in Optical Masers. Scientific American, 209(1), 34-45.
  22. ^ Hall, J. (1978). Stabilized Lasers and Precision Measurements. Science, 202(4364), 147-156.
  23. ^ Javan, Ali. "Measurement of the Frequency of Light". Annals of the New York Academy of Sciences (February 1969)
  24. ^ Javan, Ali with Blair, Betty. "Scientists Who Made A Difference: Ali Javan, The Gas Laser and Beyond", Azerbaijan International, Vol. 4:2 (Summer 1996), "[...] I'm now working in a new area that I call "Electronics at Optical Frequencies." Computers, for example, use microchips that operate at radio frequencies-MHz (Mega-Hertz) and GHz (Giga-Hertz). I'd like to take electronics out of radio frequency into the light wave frequency range. [...]"
  25. ^ "Photonics community loses HeNe pioneer Ali Javan". 15 September 2016.
  26. ^ "Biographies: Ali Javan". The Optical Society. Archived from the original on 2019-11-02.
  27. ^ "Albert Einstein World Award of Science 1993". Archived from the original on December 30, 2012. Retrieved August 13, 2013.
  28. ^ "Eurasia Academy is under construction". Retrieved 2024-12-10.
  29. ^ "Top 100 living geniuses" The Daily Telegraph (28 October 2007)

Bibliography

Quelle: http://en.wikipedia.org/wiki/Ali_Javan