Stimulated Scattering and Phase Conjugation in Photorefractive Materials

Abstract : Applications and properties of nonlinear optical materials were studied, especially photorefractive crystals. A summary includes: (1) Demonstration of a new technique for seeing an object buried in or behind a scattering medium using time-resolved holography in a spectral hole-burning material. (2) Demonstration of an all-optical switchboard using stimulated, mutually-pumped phase conjugation in a photorefractive crystal. (3) Use of optical novelty filters to detect small changes in an optical scene. (4) Invention of an electric field correlator to measure the coherence length of picosecond laser pulses, using two-wave mixing in a photorefractive crystal. (5) Derivation of a theory of beam coupling and pulse shaping picosecond light pulses in photorefractive crystals. (6) Development of a new, multiple level model to explain the nonlinear photoconductivity of barium titanate crystals. (7) Investigation of the role of absorption gratings in beam coupling in barium titanate crystals and showing how these gratings can conveniently be used to determine the density of charge in these crystals. (8) Explanation of how stimulated processes cause the curved beam paths observed in mutually-pumped and self-pumped phase conjugators.