We have observed the nonstationary polarization modulation of a speckle pattern transmitted through a photorefractive crystal under the alternating electric field of a square-wave form. A simple model based on Gaussian-beam propagation in the crystal with the diffusion type of nonlinearity is proposed to explain the main features of the experiment. Application of the phenomenon to noncontact and highly sensitive measurements of a rough surface movement is suggested.
© 1999 Optical Society of America
(120.6160) Instrumentation, measurement, and metrology : Speckle interferometry
(120.6650) Instrumentation, measurement, and metrology : Surface measurements, figure
(190.5330) Nonlinear optics : Photorefractive optics
(230.2090) Optical devices : Electro-optical devices
(230.5440) Optical devices : Polarization-selective devices
Alexei A. Kamshilin, Kimmo Paivasaari, A. V. Khomenko, and C. Fuentes-Hernández, "Polarization self-modulation of the nonstationary speckle field in a photorefractive crystal," Opt. Lett. 24, 832-834 (1999)