Stress-induced depolarization of Nd:glass in high-power laser amplifier

In the amplifier of large-aperture laser device, laser slabs will produce depolarization in the stress concentration area due to mounting and heat. The depolarization makes the laser isolation ratio unable to meet the design requirements, and there will be uncontrolled light passing through it that will amplify itself in the system and cause unpredictable damage to the slabs. It causes damaged to other optical components even more easily, and the polarization quality of the laser is also reduced, which has a considerable impact on the efficiency of the device as a result. Aiming at this problem, this paper describes the physical mechanism of the polarization characteristics of slabs caused by mounting stress and thermal stress, and puts forward the regular pattern of the assembly process parameters on the polarization characteristics of the slabs. And a series of experiments are launched to verify these mechanism and regular pattern, and also provide a method basis for optimizing its polarization characteristics.