Dynamic Holographic Interferometry with Doped Sn2P2S6 Photorefractive Crystals

We present results obtained with several schemes of dynamic interferometers based on the photorefractive parameters of Sb-doped Sn2P2S6 crystals. Besides the typical two-wave mixing scheme, we realized a lensless dynamic interferometer and a single-beam interferometer exploiting the beam fanning. The frequency range for all these schemes can be enlarged with use of heterodyne principle that also allows to measure all the parameters of the testing vibrations. We show that the phase-modulating technique can be used for testing the material's photorefractive parameters.