Accession Number : ADA194749

Title :   Studies of Coherent Beam Processing Concepts. Phase 1.

Descriptive Note : Final rept. 1 Sep 85-31 Dec 87,

Corporate Author : ROCKWELL INTERNATIONAL THOUSAND OAKS CA SCIENCE CENTER

Personal Author(s) : Yeh, Pochi A ; Chiou, Arthur E ; McMichael, Ian C ; Khoshnevisan, Monte

PDF Url : ADA194749

Report Date : Mar 1988

Pagination or Media Count : 61

Abstract : The results of theoretical and experimental studies investigate nonlinear optical (NLO) two-wave mixing phenomena for coherent beam processing. Steady state energy via two-wave mixing occurs naturally in photorefractive crystals in response to laser beams. Such energy exchange is nonreciprocal and can lead to large transfer of energy from one beam to another. There is no crosstalk between either the temporal or spatial phases of the two beams, i.e., only optical energy and not the phases is transferred. A weak signal beam with a planar wavefront can be greatly amplified with high fidelity at the expense of a strong pump beam with an aberrated wavefront. Two wave mixing can be generalized to materials other than photorefractive crystals. This project was concerned with studying the physics and applications of generalized photorefractive two-wave mixing for laser beam processing (e.g., cleanup, steering, or combining). Two-wave mixing is studied in photorefractive media for laser beam cleanup and combining. The equations governing the artificial photorefractive effects, i.e., two-wave mixing in Kerr media, are indeed quite analogous to two-wave mixing in photorefractive crystals. It was also shown that artificial photorefractive effects are also inclusive of other well-known stimulated scattering effects such as Stimulated Brillouin Scattering (SBS), when initiated by an injection process. Two-wave mixing in Kerr media concentrated on electrostrictive nonlinearities. General relationships were discovered which yielded information on electrostrictive Kerr nonlinearities of materials, simply from their linear acousto-optical parameters.

Descriptors :   *KERR MAGNETOOPTICAL EFFECT, *COHERENT OPTICAL RADIATION, ACOUSTOOPTICS, CLEANING, COSTS, CROSSTALK, ELECTROSTRICTION, ENERGY, ENERGY TRANSFER, EXPERIMENTAL DATA, FREQUENCY, INJECTION, LASER BEAMS, LIGHT SCATTERING, LINEAR SYSTEMS, LOW STRENGTH, MIXING, NONLINEAR SYSTEMS, OPTICAL PROPERTIES, PARAMETERS, PHONONS, PLANAR STRUCTURES, PROCESSING, SCATTERING, SIGNALS, STEADY STATE, STEERING, STIMULATION(GENERAL), TRANSFER, WAVEFRONTS, WAVES, OPTICAL PUMPING

Subject Categories : Optics
      Electrooptical and Optoelectronic Devices

Distribution Statement : APPROVED FOR PUBLIC RELEASE