Laser-diode-pumped eight-pass 100-W-class Nd:YAG zig-zag slab laser amplifier

Abstract

A novel laser architecture of laser-diode pumped eight pass 1064-nm Nd:YAG zig-zag slab laser amplifier with thermal birefringence compensation by use of a 90 degree quartz rotator has been developed aiming to achieve a high average power laser with high efficiency and good beam quality. With a 100 W (1 kHz) class module, the basic performance of the novel concept was examined by demonstrating an average power of 68 W with a high energy extraction efficiency of 61% for the laser mode volume at an initial small signal gain of 3.03 on single pass, and an excellent beam quality, undernegligible thermal lensing with the compensation for thermal birefringence.