Two-dimensional acousto-optic SLM

A prototype of two-coordinate spatial light modulator (SLM) based on acousto-optic diffraction in KY(WO4)(2) monoclinic crystal is proposed. The SLM design is based on a special configuration of isotropic Bragg diffraction in monoclinic crystals, which used autocollimation of the acoustic beams and operation with unpolarized light. This enables a unique design of a two-coordinate Bragg cell, which can be used as a monolithic X-Y deflector or as an SLM. Experimental results and limitations of the prototype performance are discussed in the report. Overall efficiency over 50% at 4 W of driving RF power has been demonstrated for the laser wavelength of 532 nm. Optical modulation rise/fall time is similar to 220 ns/mm for each coordinate.