Distinguished Seminar Series: "Confining light on a
chip: the science of optical micro-resonators" by Dr. Kerry Vahala
Friday, January 30, 2015 11:00 AM to 12:00 PM
CREOL Room 103
CREOL Room 103
Celebrating the International Year of Light 2015
Kerry Vahala
Jenkins Professor and Professor of Applied Physics
California Institute of Technology
Abstract:
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.
Biography:
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 IEEE and the Optical Society of America.
For additional information:
Dr. Bahaa E. A. Saleh
Dean & Director, Professor of Optics
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