The spatial characteristics of a four-wave converter of radiation in multimode waveguide with resonant nonlinearity

The quality of wave-front reversal has been studied at degenerate four-wave interaction in two-dimensional multimode waveguide with resonant nonlinearity using the Point-Spread Function (PSF) method. It has been shown that over time the PSF-module width, defined by paraxial waveguide modes, decreases, reaching a steady value, slowly varying with increasing the pump intensity. The PSF-module width first increases and then decreases with the increasing of number of pump wave mode when the coincidence of the numbers of single-mode pump waves.