利用GaAs晶体作为可饱和吸收体, 实现了掺镱光子晶体光纤激光器的被动调Q输出。实验用掺杂光子晶体光纤的芯径为21 μm, 数值孔径为0.04, 在实现了大模场面积的同时, 保证了激光器的单模运转, 从而得到高光束质量的激光输出。实验使用高功率半导体激光器作为抽运源, 采用自行研制的耦合系统将抽运光耦合进入光子晶体光纤的包层中。在激光器平均输出功率为5.8 W时, 实验得到的最短输出激光脉冲为80 ns, 重复频率为6.7 kHz。

A passive Q-switched Yb-doped photonics crystal fiber(PCF) laser is demonstrated using GaAs as the saturable absorber. The PCF core has a diameter of 21 μm and an numerical aperture(NA) of 0.04, resulting in transversal single mode wave guiding for 1020～1150 nm light, ensures the good beam quality of the laser. The laser is pumped by a high power laser diode .The pumped laser is coupled to the cladding of PCF through a self-regulating coupling system. A shortest pulse duration as 80 ns was obtained with the maximum repetition rate of 6.7 kHz, when the maximum average output power of PCF laser is 5.8 W.