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 con...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.展开更多
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)。
文摘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.
