NONLINEAR DYNAMICS OF OPTICAL SWITCHING FRONTS IN CDS

A two-level model for impurity-related optical switching in lightly do ped CdS crystals is developed which explains dynamical switching betwe en a low and a high transmissivity slate by a bleaching front traversi ng the crystal with a velocity of several 10(8) cm/s and offers detail ed insight into the internal nonlinear spatio-temporal dynamics of the process. The predicted front is detected experimentally by a 90 degre es pump-and-probe configuration. The front velocity in the experiment agrees well with the theoretical prediction.