Tang Yulong, Xu Lin, Yang Yi, Xu Jianqiu
Shanghai Institute of Optics and Fine Mechanics, Shanghai 201800, China.
Opt Express. 2010 Oct 25;18(22):22964-72. doi: 10.1364/OE.18.022964.
Gain-switched by a 1.914-µm Tm:YLF crystal laser, a two-stage Tm(3+) fiber laser has been achieved 100-W level ~2-µm pulsed laser output with a slope efficiency of ~52%. With the 6-m length of Tm fiber, the laser wavelength was centered at 2020 nm with a bandwidth of ~25 nm. Based on an acousto-optic switch, the pulse repetition rate can be modulated from 500 Hz to 50 kHz, and the laser pulse width can be tuned between 75 ns and ~1 µs. The maximum pulse energy was over 10 mJ, and the maximum pulse peak power was 138 kW. By using the fiber-coiling-induced mode-filtering effect, laser beam quality of M2 = 1.01 was obtained. Further scaling the pulse energy and average power from such kind of gain-switched fiber lasers was also discussed.
由1.914微米的Tm:YLF晶体激光器进行增益开关控制，一台两级Tm(3+)光纤激光器实现了100瓦级、波长约2微米的脉冲激光输出，斜率效率约为52%。使用6米长的Tm光纤时，激光波长中心位于2020纳米，带宽约为25纳米。基于声光开关，脉冲重复频率可在500赫兹至50千赫兹之间调制，激光脉冲宽度可在75纳秒至约1微秒之间调谐。最大脉冲能量超过10毫焦，最大脉冲峰值功率为138千瓦。通过利用光纤盘绕引起的模式滤波效应，获得了M2 = 1.01的激光束质量。还讨论了进一步扩大此类增益开关光纤激光器的脉冲能量和平均功率的问题。
