Losses of Optical Power in a Laser resonator, caused by depolarization in a laser crystal.

Thermal effects in a Gain medium of a high-power laser can cause significant power losses through depolarization, IF a gain medium without intrinsic birefringence is used and the Laser Resonator contains an element with high losses for one of the Polarization directions. The reason for this is that the temperature gradients in the gain medium induce mechanical stress and thus some amount of birefringence, with the direction of the local axis varying over the beam cross-section. As a result, an originally linear polarization state is distorted, SO that losses can occur at a polarizing intracavity element.