Competition of modes in an optically heterodyned acoustooptic generator

An acoustooptic generator in which the feedback signal is produced using optical heterodyning is studied theoretically and experimentally. The development of oscillations in this system is analysed by computer simulations. It is shown that the competition of modes caused by nonlinearity of the acoustooptic interaction can result in the degeneration of the generation spectrum and the establishment of a single-mode regime. The dependence of the generator linewidth on the parameters of the system is studied.