MODULATION Z-SCAN TECHNIQUE FOR CHARACTERIZATION OF PHOTOREFRACTIVE CRYSTALS

We propose a simple single-beam configuration for characterization of the amplitude, speed of growth, and polarization properties of the pho toinduced refractive-index change that is due to a drift photorefracti ve mechanism of nonlinearity in crystals, namely, the modulation Z-sca n technique, based on the modulation of an externally applied electric field. The results of a simple theoretical model developed for one-di mensional parabolic photorefractive lens formation in this configurati on are illustrated by original experiments with a semi-insulating GaAs crystal at lambda = 1.06 mu m. (C) 1996 Optical Society of America