Polarization Self-Modulation Of Speckle Patterns In A Bundle Of Photorefractive Crystals

The experimental and theoretical studies of a polarization self-modulation effect in photorefractive Bi12TiO20 crystals are presented. We developed an approximate theory that allows optimizing the performance of the adaptive sensor based on the polarization self-modulation effect. To diminish external voltage simultaneously keeping the aperture of the sensor large enough, we constructed a sensor consisted of several Bi12TiO20 crystals of different orientations. High sensitivity and adaptability to slow environment changes of the proposed sensor make it useful for various applications, particularly for laser ultrasound detection. (C) 2000 American Institute of Physics. [S0021-8979(00)05917-X].