Accession Number : ADP006761

Title :   Numerical Analysis of Photorefractive Grating Formations at Large Modulation,

Corporate Author : ROME LAB GRIFFISS AFB NY

Personal Author(s) : Brost, George A.

Report Date : 22 MAY 1992

Pagination or Media Count : 4

Abstract : Enhancements in the two-beam coupling gain can be achieved in cubic crystals of the BSO type by the use of nonstationary external conditions such as the application of a dc field along with a moving interference pattern or by the application of an alternating electric field. However, for modulation index, m, greater than about 0.1 the performance falls off significantly with increasing m. Some success has been achieved in obtaining steady-state solutions of the nonlinear equations in the presence of moving fringes. These numerical calculations were accomplished by expansion of the variables into their Fourier components or by perturbation techniques. In this paper we model the photorefractive grating formation by a finite difference method. This approach is quite general. The numerical solutions predict the photorefractive behavior at large modulation for stationary and nonstationary photorefractive recording techniques.

Descriptors :   *GRATINGS(SPECTRA), BEHAVIOR, COUPLINGS, CRYSTALS, EQUATIONS, EXPANSION, EXTERNAL, GAIN, INTERFERENCE, MODELS, MODULATION, PERTURBATIONS, STEADY STATE, VARIABLES, REFRACTION, ELECTRIC FIELDS, SYMPOSIA.

Subject Categories : Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE