Kerry Vahala: Jenkins Professor and Professor of Applied Physics, California Institute of Technology
Jenkins Professor and Professor of Applied Physics, California Institute of Technology
Confining Light on a Chip: The Science of Optical Micro-Resonators
November 6, 2013 | 4:00pm | ESB 2001
Faculty host: John Bowers
Video and presentation slides will be posted on the Institute website within a week following the seminar.*
Like a tuning fork for light, optical resonators have a characteristic set of frequencies at which it is possible to confine light waves. At these frequencies, optical energy can be efficiently stored for lengths of time characterized by the resonator Q factor, roughly the storage time in cycles of oscillation. In the last ten years there has been remarkable progress in boosting this storage time in micro and millimeter-scale optical resonators. Chip-based devices have attained Q factors of nearly 1 billion and micro-machined crystalline devices have provided Qs exceeding 100 billion. The resulting long, energy-storage times combined with small form factors have made it possible to access a wide range of nonlinear phenomena and to create laser devices that operate with remarkably low turn-on powers. Also, new science has resulted from radiation-pressure coupling of optical and mechanical degrees-of-freedom in the resonators themselves. I will review some of these results including parametric oscillators, optical frequency microcombs and microwave generation. The adaptation of resonator fabrication methods to optical delay lines as long as 27 meters on a silicon wafer will also be discussed.
Professor Vahala received his BS, MS and Ph.D. degrees at Caltech. His research group has pioneered a class of optical resonators that hold the record for highest optical Q on a semiconductor chip. They have applied these devices to study a wide range of nonlinear phenomena including the first demonstration of parametric oscillation in a micro cavity, now the basis for frequency micro combs. His research in this subject also led to the demonstration of dynamic backaction, a long-anticipated interaction of mechanics and optics mediated by radiation pressure that is responsible for opto-mechanical cooling and recent realizations of mechanical amplification by stimulated phonon emission. Professor Vahala was involved in the early effort to develop quantum-well lasers for optical communications and received the IEEE Sarnoff Award for his research on quantum-well laser dynamics. He has also received an Alexander von Humboldt Award for his work on ultra-high-Q optical microcavities and is a fellow of the Optical Society of America.
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*Video and slides only available for seminars if approved.