Light pulse manipulation in Sn 2 P 2 S 6

Abstract Acceleration and deceleration of light pulses when writing a refractive index grating in Sn 2 P 2 S 6 is described. It is shown that in crystals with two types of movable charge carriers short pulses are accelerated while long pulses are delayed or vice versa, depending on the orientation of the polar axis

Nearly degenerate two-beam coupling in photorefractive crystals with two species of movable carriers

Two-beam intensity coupling is calculated for photorefractive crystals with two types of movable charge carrier in the undepleted-pump approximation. The analytical expressions are derived for the temporal evolution of the space-charge field; for weak coupling they are used for calculation of the transmitted beam intensities. The results of the calculation are compared with the experimental observations in photorefractive tin hypothiodiphosphate (Sn 2 P 2 S 6 ). All experimental data are in reasonable quantitative agreement with the calculations. © 1998 Optical Society of America [S0740-3224(98

Exact Bright and Dark Spatial Soliton Solutions in Saturable Nonlinear Media

We present exact analytical bright and dark (black and grey) solitary wave solutions of a nonlinear Schrodinger-type equation describing the propagation of spatial beams in media exhibiting a saturable nonlinearity (such as centrosymmetric photorefractive materials). A qualitative study of the stationary equation is carried out together with a discussion of the stability of the solutions.Comment: 16 pages, 5 figure