Time dependence of the point spread function of a four-wave converter in a waveguide with thermal nonlinearity

The time dependence of a quality of wave-front reversal has been analyzed at four-wave interaction in a waveguide with thermal nonlinearity. The influence of waveguide parameters and mode structure of pumping waves on time dependence character has been investigated. It has been shown, that increases of number of single-mode pumping waves lead to decreases of difference in point spread function width in steady state and initial state.