IEEE Photonics Society

Boston Photonics Society Chapter

Boston Chapter of the IEEE Photonics Society


October 5, 2018
3 PM

Boston University Photonics Center PHO339

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Measuring Everything You've Always Wanted to Know About a Light Pulse

Prof. Rick Trebino, Georgia Institute of Technology, Atlanta, GA


Prof. Rick Trebino, Georgia Institute of Technology, Atlanta, GA

Abstract:  The vast majority of the greatest scientific discoveries of all time have resulted di-rectly from more powerful techniques for measuring light.  Indeed, our most im-portant source of information about our universe is light, and our ability to extract information from it is limited only by our ability to measure it.

Interestingly, most of the light in our universe remains immeasurable, involving long pulses of relatively broadband light, necessarily involving ultrafast and extremely complex temporal variations in their intensity and phase. As a result, it is important to develop techniques for measuring, ever more completely, light with ever more com-plex submicron detail in space and ever more complex ultrafast variations in time. The problem is severely complicated by the fact that the timescales involved corre-spond to the shortest events ever created, and measuring an event in time seems to require a shorter one, which, by definition, doesn’t exist!

Nevertheless, we have developed simple, elegant techniques for completely measuring such light, using the light to measure itself and yielding a light pulse's in-tensity and phase vs. time and space. One technique involves making an optical spec-trogram of the pulse using a nonlinear optical medium and whose mathematics is equivalent to the two-dimensional phase-retrieval problem—a problem that’s solvable only because the Fundamental Theorem of Algebra fails for polynomials of two varia-bles. In addition, we have recently developed simple methods for measuring the complete spatio-temporal electric field [E(x,y,z,t)] of an arbitrary, potentially complex light pulse without the need to average over multiple pulses.


Biography:  Rick Trebino was born in Boston, Massachusetts on January 18, 1954. He received his B.A. from Harvard University in 1977 and his Ph.D. degree from Stanford University in 1983. His dissertation research involved the development of a technique for the measurement of ultrafast events in the frequency domain using long-pulse lasers by creating moving gratings. He continued this research during a three-year term as a physical sciences research associate at Stanford.

In 1986, he moved to Sandia National Laboratories in Livermore, California, where he studied higher-order wave-mixing, nonlinear-optical perturbation theory using Feynman diagrams, and ultrashort-laser-pulse techniques with application to chemical dynamics measurements and combustion diagnostics. There he developed Frequency-Resolved Optical Gating (FROG), the first technique for the measurement of the intensity and phase of ultrashort laser pulses.

In 1998, he became the Georgia Research Alliance-Eminent Scholar Chair of Ultrafast Optical Physics at the Georgia Institute of Technology, where he currently studies ultrafast optics and applications.

Prof. Trebino has received several prizes, including the SPIE’s Edgerton Prize, and he was an IEEE Lasers and Electro-Optics Society Distinguished Lecturer. He is a Fellow of the Optical Society of America, the American Physical Society, and the American Association for the Advancement of Science. His interests include adventure travel, archaeology, and primitive art.


Location:  Boston University Photonics Center PHO339