Numerical analysis of a multi-pass pumping Yb:YAG thick-disk laser with minimal heat generation

Abstract

A theoretical model is established to describe the dynamic behavior and fractional thermal load of a multi-pass pumping Yb:YAG thick-disk laser, which is pumped at 1030 nm and emits laser radiation at around 1048 nm. The fractional thermal load, the temperature of the thick-disk crystal, and the operational properties for different ambient temperatures and different output coupler transmissions are investigated in detail. The results show that the pump saturation effect and the laser threshold are sensitive to the ambient temperature and the output coupler transmission, which affect the fractional thermal load and the laser extraction efficiency. Furthermore, a new design scheme is proposed to realize "zero thermal load" throughout the output range by dynamically adjusting the output coupler transmission.