Thermal and non-thermal lensing of Yb:YAG and Tm:YAG thin slab laser gain media

摘要

Knowledge of the lensing caused by pumping of laser gain media is essential for the design of high power amplifiers. The thermally induced lens is well known, but the difference in polarizability of excited and unexcited ions can also produce a refractive index change which is comparable to the thermally induced change [1]. For intensely pumped Yb:YAG, the effect can be one order of magnitude higher than the thermal effect [2]. This paper aims to demonstrate the non-thermal lensing component of intensely pumped Yb:YAG and Tm:YAG thin slabs.