Abstract

We report the first studies of photorefractive semiconductors by using a picosecond optical parametric generator (OPG). We perform nonresonant degenerate four-wave mixing (DFWM) in CdTe and GaAs crystals far away from the band-gap, while the previous studies of optical nonlinearities using parametric devices have been carried out only at the resonant fundamental transitions. Consequently, application of OPG for studied of nonresonant interaction opens a possibility for a direct investigation of the wavelength dependence of mid-gap impurity related photoexcitation as well as time-resolved measurements of carrier and space charge field dynamics.

© 1998 IEEE