Orthogonally polarized self-mode-locked Nd:YAG laser with tunable beat frequencies

Abstract

An orthogonally polarized self-mode-locked Nd: YAG laser is demonstrated in a short linear cavity. Under an incident pump power of 8.2 W, the average output power can be measured to be 3.8 W. The beat frequency.fc between two orthogonally polarized mode-locked components is observed and increases linearly with an increase in the incident pump power. The origin of the beat frequency is utterly confirmed to be caused by the thermal-stress-induced birefringence in the Nd: YAG crystal and is theoretically simulated. The present result provides a promising method to achieve orthogonally polarized mode-locked lasers with tunable beat frequency.