Nd:YAIG Laser Cavity Loss due to an Internal Brewster Polarizer

When an internal Brewster plate is used to polarize a Nd:YAIG laser, its output power generally decreases. This is shown to be largely due to the thermally induced birefringence in the laser rod, which causes a polarization rotation inside the optical cavity and hence a reflection loss at the polarizer. Calculation of this loss for a typical laser has been made and is compared to observed decreases in output power.