Optical Devices Research Group
Professor Garmire's research group is currently composed of ten PhD
students. Collaborations are currently underway with Lute Maleki from
JPL, Alan Kost and Tom Hasenberg from Hughes Research Laboratories.
The research interest of the group are broadly based in the areas of
nonlinear optics, integrated and fiber optics, semiconductor lasers and
infrared detectors. Applications envisaged for such devices range from
optical computing and neural nets to optical communications and
- Nonlinear Optical Properties of Semiconductors: Nonlinear
absorption and nonlinear refractive index are studied in
semiconductors: InAs, GaAs, and CdZnSe. Investigations are made with
lasers tuned to near the bandgap using either nonlinear transmission or
pump-probe techniques. Special emphasis is placed on layered media such
as multiple quantum wells, Bragg reflectors, n-i-p-i structures and
- Applications: Nonlinear materials in surface-normal configurations
are being explored for advanced Spatial Light Modulators, optical
bistable switches, phase modulators and fast, high contrast SLM's.
Other applications demonstrated include Q-switching of YAG lasers. New
concepts have been developed for improved far-infrared focal plane
- Photorefractive Effect: Studies of enhanced two-wave mixing in near
the band-edge in GaAs and other semiconductors have been explored,
particularly for phase-conjugate resonators. Studies have also been
made of the photorefractive effect and fixing gratings in LiNbO3
- Semiconductor Lasers: GaAs laser arrays in properly designed
external cavities provide power diffraction limited output. Temporal
mode-locking provides psec pulses. Both systems have been investigated
both experimentally and theoretically, as well as basic nonlinear
optical phenomena in such systems such as frequency-locking and chaos.
Long-wavelength lasers, planned to operate in the 3 µ m wavelength
region have been explored, as well as double carrier confinement lasers
operating at 1.3 µ m were built.
- Integrated Optics: Semiconductor modulators and bistable devices,
LiNbO3 modulators, polymer films and couplers, and a ring
interferometer have been fabricated in our clean room and fully
characterized. Quasi-phase matching for harmonic generation is
presently being studied.
- Fiber Optics: Recent studies entail fiber monitoring of bridges,
power-by-light down a fiber, combined spatial-temporal CDMA systems,
color center formation in UV fibers, a study of the simulated Raman
effect in fibers, and hollow metal waveguides for far infrared.
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