OPTICAL-PHASE CONJUGATION USING DX CENTERS

Optical phase conjugation is measured in a doped semiconductor contain ing DX centers. This is to our knowledge the first observation of a st eady-state optical nonlinearity in these materials. Phase-conjugate re flectivities of 0.3% result from four-wave mixing in AlGaAs:Te at inte nsities of the order of 1 mW/cm(2). The measured nonlinear-optical sen sitivity of similar to 0.4 cm(2)/J is 2 orders of magnitude larger tha n that in ferroelectric photorefractive crystals. (C) 1996 Optical Soc iety of America.