Analysis and Evaluation of Laser-Induced Damage of Zig-Zag Slab Laser Amplifier

Abstract

The laser damage on a total internal reflection (TIR) surface as well as on entrance and exit faces was evaluated to design a zig-zag slab laser. Incorporating a phase shift by the Goos–Hänchen effect on a TIR surface of a laser slab in contact with water, formulas for a laser-induced damage threshold (LIDT) were modified. We determined a method for the designing the geometry of a zig-zag slab laser based on LIDT. A thin film for anti-reflection (AR) with a high LIDT must be formed on the entrance and exit faces of a laser slab glass. A sol–gel thin film was adopted for the AR coating of a high-power laser due to its high LIDT. We devised an effective dip-coating method to form a sol–gel thin film uniformly on a small area. The LIDT of the sol–gel thin film was measured and evaluated with a single mode Q-switch Nd:YAG laser by a one-on-one measurement technique.