Temperature characteristics and stabilization of orthogonal polarization two-frequency Nd3+:YAG microchip lasers

The temperature dependence of the beat frequency and polarization azimuth of fiber-guiding laser diode pumped Nd(3+):YAG microchip lasers emitting orthogonal linear polarization at two frequencies is investigated, and we found a resemblance to the features that result from the application of mechanical force. The experimental observations are well described by the cavity model, which indicates that temperature change induces weak phase anisotropy in addition to the original phase anisotropy with general mutually inclined axes of anisotropy. With a servo control to keep the beat frequency constant, the beat and central laser frequencies are simultaneously stabilized to within +/-0.1 MHz and +/-0.35 GHz, respectively.