Up conversion and excited state absorption analysis in the Tm:YAG disk laser multi-pass pumped by 1 μm laser  

作　　者：Enmao Song Guangzhi Zhu Hailin Wang Hantian Chen Yefeng Qian Kozlov Aleksei Xiao Zhu 

机构地区：[1]School of Optical and Electronic Information,Huazhong University of Science and Technology,Wuhan 430074,China [2]National Engineering Research Center for Laser Processing,Wuhan 430074,China [3]POLYUS Research Institute of M.F.Stelmakh Joint Stock Company,Moscow 117342,Russia

出　　处：《High Power Laser Science and Engineering》2021年第1期77-85,共9页高功率激光科学与工程（英文版）

基　　金：supported by the National Natural Science Foundation of China(NSFC,No.61975060);the Fundamental Research Funds for the Central University(HUST,No.2016YXMS213)。

摘　　要：We present a 2 μm Tm:YAG disk laser multi-pass pumped by a 1 μm laser. The transitions in competition of up conversion(UC) and excited state absorption(ESA) are analyzed in detail based on a numerical model that considers stimulated emission, fluorescence, non-radiative decay, UC, and ESA, showing good agreement with experiments. The proportions and fractional thermal loads of all transitions are derived quantitatively. The results show that UC and ESA are critical in Tm:YAG disk lasers, resulting in a decrease in the absorbed pump power and temperature after lasing for two different disk thicknesses. In addition, although the absorbed pump power of the 0.5 mm disk is lower than in the1 mm case, its relatively weak UC and ESA and low total fractional thermal load can improve laser performance. A0.5 mm Tm:YAG disk laser thus delivered the maximum output power of 1.05 W with beam quality of M_(x)^(2)= 2.02 and M_(y)^(2)= 2.03.

关 键 词：mid-infrared laser thermal effects THULIUM 

分 类 号：TN248[电子电信—物理电子学]