Shi Bingnan, He Guanbai, Mao Jiajia, Wang Feifei, Yang Kejian, Zhang Baitao, He Jingliang
Appl Opt. 2021 Jan 1;60(1):186-193. doi: 10.1364/AO.413502.
A high-gain two-stage double-pass off-axis : picosecond laser amplifier has been developed. The comprehensive influence of crystal doping concentration and pump beam quality on the small-signal gain of the : amplifier is theoretically analyzed with a model developed by considering energy transfer upconversion and pump light absorption saturation effect. The thermal effect of : crystal with different doping concentrations, undoped end cap lengths, and pump beam quality is investigated as well. Based on the theoretical analysis, a high-gain two-stage and double-pass off-axis : amplifier based on picosecond fiber seed source is realized by choosing long-composite low-doping : crystal and with high brightness laser diode pumping, delivering a gain of 28 dB and an output pulse energy of 67.5 µJ at a repetition rate of 200 kHz.
已研制出一种高增益两级双程离轴皮秒激光放大器。利用考虑能量转移上转换和泵浦光吸收饱和效应建立的模型，从理论上分析了晶体掺杂浓度和泵浦光束质量对该放大器小信号增益的综合影响。还研究了不同掺杂浓度、未掺杂端帽长度和泵浦光束质量的晶体的热效应。基于理论分析，通过选择长复合低掺杂晶体并采用高亮度激光二极管泵浦，实现了基于皮秒光纤种子源的高增益两级双程离轴放大器，在200kHz重复频率下增益为28dB，输出脉冲能量为67.5μJ。
