Optical nonlinearities of glasses doped with semiconductor microcrystallites

The origin of optical nonlinearities of glasses doped with CdS(x)Se(1-x) microcrystallites is studied both experimentally and theoretically. At room temperature a large shift ( congruent with50 meV) of the absorption spectrum to higher energies is observed in a CdS(x)Se(1-x) glass with increased light intensity. This blue shift is analyzed by using a semiconductor plasma theory. Experimental and theoretical results suggest that band filling is the dominant mechanism for the observed nonlinearity. An independent measurement for the intensity-dependent dispersive changes is presented.