波长为2 μm的中红外掺铥光纤激光器可广泛应用于激光医疗、人眼安全雷达、非金属材料加工、光电对抗等领域, 具有其他类型光纤激光器不可替代的重要作用。报道了一种全光纤结构波长可调谐被动锁模掺铥光纤激光器。该光纤激光器利用半导体可饱和吸收镜与高双折射率光纤环镜实现锁模皮秒脉冲与波长可调谐激光输出。高双折射率光纤环镜由2×2激光分束器和高双折射光纤组成, 实验中通过改变光纤环镜中高双折射光纤的温度, 得到了中心波长可调谐范围为1952~1967 nm, 调谐宽度为15 nm, 重复频率为 29 MHz, 最短脉冲宽度为6 ps的可调谐皮秒脉冲激光输出。

The research on medium-infrared thulium-doped fiber lasers at 2 μm wavelength is widely used in the field of laser medical, eye-safe radar, non-metal material processing, and electro-optical countermeasure system, it has an irreplaceable role compared with other wavelength fiber lasers. An all-fiber wavelength-tunable passively mode-locked thulium-doped fiber laser is reported. This laser realizes picosecond pulses and tunable wavelength by using a semiconductor saturable absorber mirror and a high-birefringence fiber optical loop mirror. This high-birefringence fiber optical loop mirror consists of a 2×2 coupler with output ports spliced to a high-birefringence fiber. The tunable picosecond pulse laser output is obtained by changing the temperature of the high-birefringence fiber in a fiber optical loop mirror. The center wavelength tunable range is from 1952 to 1967 nm, the tuning width is 15 nm, the repetition rate is 29 MHz, and the shortest pulse width is 6 ps.