Accession Number : ADP008615

Title :   Enhanced Photorefractive Effects with a dc Field and Moving Grating in GaP at 633 nm,

Corporate Author : CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF ELECTRICAL AND COMPUTER ENGINEERIN G

Personal Author(s) : Ma, Jian ; Taketomi, Yoshinao ; Fainman, Yeshaiahu ; Ford, Joseph E. ; Lee, Sing H.

Report Date : 22 MAY 1992

Pagination or Media Count : 4

Abstract : Photorefractive (PR) devices have found applications in optical computing, image processing and pattern recognition, because PR materials provide unique features such as real time operation, optical gain, storage, nonlinear operations, phase conjugation and correlation. New PR materials are being investigated in order to meet the device and systems requirements of sensitivity, speed, and operation wavelength (e.g., response to the near infrared spectral range for systems operated with semiconductor lasers). Compound semiconductors may satisfy these requirements. For example, optical signal amplification by two-beam coupling and amplified phase-conjugate beam reflection by four-wave mixing have been reported in GaAs and InP at the wavelength of 1.06 microns. Recently GaP was shown to possess a relatively weak PR effect in the spectral range of 0.6 to 0.9 microns. In this manuscript we report enhancement of the PR effect in GaP using an externally applied electric field and moving grating. Several figures of merit of GaP, i.e., steady-state index change, absorption coefficient, response time and PR sensitivity were characterized.

Descriptors :   *REFRACTION, *OPTICAL PROCESSING, *IMAGE PROCESSING, GRATINGS(SPECTRA), PATTERN RECOGNITION, GALLIUM PHOSPHIDES, CRYSTALS, ELECTRIC FIELDS, OPTICAL MATERIALS, FOUR WAVE MIXING.

Subject Categories : Electrooptical and Optoelectronic Devices
      Optics
      Cybernetics

Distribution Statement : APPROVED FOR PUBLIC RELEASE