OPTICAL NONLINEARITIES IN SEMICONDUCTOR-DOPED GLASSES NEAR AND BELOW THE BAND-EDGE

We present a brief review of our recent experimental results on optica l nonlinearities in semiconductor-doped glasses. It is shown that even below the absorption edge the nonlinearities are determined by nonlin ear absorption. The optical Kerr effect is found to have a susceptibil ity which is comparable to that for nonlinear refraction. We also find that in degenerate four-wave mixing the observed intensity dependence can be strongly influenced by nonlinear absorption.