工作在2 μm波段的脉冲掺铥光纤激光器, 可望在遥感探测、相干雷达、空间光通信、激光医疗和特种材料加工等领域获得重要应用。目前, 利用波长在1.55 μm附近的脉冲掺铒光纤激光器作泵浦源的增益开关掺铥光纤激光器是实现全光纤结构纳秒脉冲掺铥光纤激光器的理想方式之一。采用实验研发的纳秒脉冲掺铒激光器作种子源, 研制了全光纤MOPA(master oscillator power amplifier)结构的纳秒脉冲掺铒光纤激光器, 输出波长1 547 nm, 脉冲频率100 kHz, 脉冲宽度50 ns, 平均功率1 W, 单脉冲能量10 μJ。使用该脉冲掺铒光纤激光器抽运掺铥光纤, 实现了波长1 963 nm的增益开关脉冲激光输出。该掺铥光纤激光器为全光纤结构, 重复频率100 kHz, 最小脉宽47 ns, 最大单脉冲能量100 nJ。激光输出稳定可靠, 更高的单脉冲能量, 平均功率和峰值功率可由进一步级联光纤放大器实现。

We present an all-fiber gain-switched thulium-doped fiber laser which produces pulses with 47 ns duration at a repetition rate of 100 KHz. The central wavelength and full wave half maximum (FWHM) were 1 963 nm and 3.7 nm respectively. The pulsed pump source, providing a 100 kHz pulse at 1 547 nm with 50 ns duration and energy of 10 μJ to gain switch the laser, was a novel nanosecond-pulsed Erbium-doped fiber laser modulated by semiconductor saturable absorber mirror (SESAM). The whole system was simple and compact, and operated with high stability and reliability. High energy can be further improved by use of additional cascaded fiber amplifiers.