Acousto-optic stabilization of the intensity of a laser beam

A system for stabilization of the intensity of a laser beam based on an acousto-optic modulator is theoretically and experimentally studied. An equation that describes dynamic processes in the system and various working regimes is derived. It is demonstrated that the stabilization coefficient depends on the transfer coefficient of the feedback circuit and the position of the working point on the amplitude characteristic of the acoustooptic interaction. An experimental prototype of the stabilization system is based on a paratellurite acousto-optic cell. The system stabilizes the intensity with a coefficient of 78 in a frequency band of 15–180 Hz.