Abstract

Unidirectional and hence single frequency operation of a ring laser is generally achieved using an intracavity Faraday isolator. An alternative technique, demonstrated recently for Nd:YAG,¹ dye,² and Ti sapphire ring lasers/ makes use of the acousto-optic (AO) effect. This technique offers significant advantages over the Faraday isolator approach, particularly for miniature solid-state lasers, “since only one extra component is required. Also, the technique does not rely on polarization discrimination and is therefore well suited for use in lasers containing biréfringent elements, for example, laser media and frequency doublers. Additionally, an AO device offers the possibility of Q-switching the laser output to obtain higher peak powers. To the best of our knowledge, an adequate explanation for the non-reciprocal behavior of a traveling-wave AO Q-switch has not yet been reported, A knowledge of the mechanism is nevertheless important if better optimized devices yielding higher loss-differences are to be made.

© 1992 Optical Society of America