Wave mixing in nominally undoped Sn2P2S6 at high light intensities

Abstract

The intensity dependence of the photorefractive response of Sn2P2S6 is studied for the Kr+-laser wavelength of 647 nm and pump-beam intensities of up to 10 W/cm(2). A considerable enhancement of the two-beam coupling gain factor with increasing intensity at a grating spacing of a parts per thousand integral 1 mu m is attributed to a light-induced increase of the effective trap density. The large gain reached at high intensities is applied for the build up of a double phase conjugate mirror with a sub-millisecond switch-on time.