PHOTOREFRACTIVE COHERENCE-GATED INTERFEROMETRY

We have demonstrated a novel optical interferometric technique for a h ighly scattering environment, using photorefractive coherence gating. A two-wave mixing process in a photorefractive barium titanate crystal effectively reduces scattering noise, and we have successfully detect ed interferometric signals through scattering media of up to 17 mfp, w ith a high visibility. We have also demonstrated a two-dimensional thi ckness measurement of an optically scattering thin film using our new interferometry. (C) 1998 American Institute of Physics. [S0034-6748(98 )01911-X].