实验研究了高平均功率输出的光子晶体光纤飞秒激光系统。系统中振荡器和放大器均使用保偏型掺Yb3+双包层大模场面积光子晶体光纤(LMA-PCF)为增益介质,具有极低非线性系数、很高的增益系数,并能保证很好的环境稳定性。系统研究了种子光功率、脉冲宽度、脉冲啁啾和放大器抽运光功率等参数对系统输出飞秒激光脉冲宽度的影响。在输入种子光平均功率为180 mW,放大器抽运功率为40 W时,获得平均功率16 W输出(对应单脉冲能量320 nJ),脉冲宽度压缩到39 fs。

A femtosecond fiber laser system with high average power and short pulse duration is demonstrated,whose oscillator and amplifier are based on an Yb-doped single-polarization large-mode-area photonic crystal fiber (LMA-PCF) with low nonlinearity, high gain and nice environmentally stability. The dependence of the output pulse duration on the pulse energy, duration and chirp of seed light from oscillator and the pump power of amplifier is studied. The fiber laser amplifier generates 16 W average power, corresponding to 320 nJ pulse energy, at 40 W pump power, when the seed light is fixed at 180 mW average power, and the pulse duration is compressed to 39 fs after gratings.