SC155 Ultrashort Laser Pulse Measurement

Tuesday, May 6, 1:30 p.m. - 5:30 p.m.
Rick Trebino; Georgia Tech, USA

Course Description
Probably no field in science and technology is beset by more confusion and misconceptions than that of the measurement of ultrashort laser pulses. There are several reasons: the events involved are unimaginably short, most measurement techniques yield results that can’t be confirmed, and competition is fierce to sell lasers or claim world records for generating the shortest pulses. Worse, obsolete techniques introduced decades ago continue to find common use, despite their uninformative and misleading nature. In addition, new techniques are introduced frequently, and most don’t actually work!

Interestingly, most ultrashort-pulse measurement problems have now been solved, and the techniques are accurate, reliable, convincing and easy to work with. This course is designed for anyone who would like to learn how to (correctly!) measure ultrashort laser pulses using techniques that work. It will begin by describing the basics of ultrashort laser pulses and answer the question: what characteristics of them do we need to measure? It will then describe earlier methods (autocorrelation) and why they are now obsolete. Finally, it will consider newer methods: some that work and some that don’t—and why. It will cover a combination of spectrographic and interferometric methods for measuring almost any pulse that can be generated, from few-femtosecond, near-single-cycle pulses to noisy trains of the most complex pulses ever generated.

Benefits and Learning Objectives
This course should enable you to:

• Explain the fundamental mathematics and physics behind these methods.
• Measure almost any ultrashort pulse.
• Verify that your measurement is correct.
• Measure ultrafast polarization variation.
• Measure extremely complex pulses.
• Measure the complete spatio-temporal electric field of a focused pulse.
• Measure the complete spatio-temporal electric field of an unfocused ultrashort pulse on a single shot using only two optical elements.
• Discuss how to determine which technique is right for your application.

Intended Audience
Anyone using ultrashort pulses for any reason will find this course important for his or her work. Anyone interested in why as seemingly obscure a mathematical fact as the failure of the Fundamental Theorem of Algebra for polynomials of two variables can be responsible for a wide range of successful techniques for measuring ultrashort pulses w

Instructor Biography
Rick Trebino developed the first technique for the measurement of the time-dependent intensity and phase of ultrashort laser pulses. He is 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. He has received several prizes, including the SPIE’s Edgerton Prize, and he is a fellow of the Optical Society of America and the American Physical Society. His interests include adventure travel, archaeology and primitive art.