Resonant behavior of the temporal response of the photorefractive InP:Fe under dc fields

The pump beam intensity dependent temporal response of the two-wave mixing in InP:Fe crystals under dc fields at stabilized temperature has been studied. We observed a resonant behaviour of the rise time of the photoinduced grating like the coherent amplification gain. Numerical solutions of the coupled field and material differential equations have been performed with a time dependent fringe modulation in the sample volume. The temporal evolution of the signal beam output intensity has been described taking into account the nonlinearity effect at large modulations. Preliminary theoretical and experimental results are in rather good agreement.