Acousto-Optic Deflector with Heat Removal from the Piezotransducer by Sound Insulation of a Heat Radiator

Abstract

A method is proposed for removing heat from the transducer of an acousto-optic deflector without substantial acoustic damping. The rear surface of the transducer and the heat–radiator surface are kept in contact through a thin sound-insulating fluid layer. The method is based on the considerable difference in the complex acoustic impedances for shear vibrations of fluids and a solid (the piezotransducer) by means of efficient heat transfer through the fluid. In the experiment, a continuous operation mode of the acousto-optic deflector is achieved with an acoustic wave intensity of more than 20 W/cm2. The acousto-optic deflector has been created that operates in the Bragg diffraction mode with a phase–modulation index of 3π with an input continuous controlling electric power of 3 W. The deflector characteristics for a light wavelength of 1.06 μm are as follows: diffraction efficiency no less than 90% in the 25 MHz frequency band at an absolute scanning angle of 40 mrad.