利用普通大模场面积掺镱保偏双包层光纤作为增益介质,采用啁啾脉冲放大技术搭建了全保偏光纤飞秒激光放大系统。由于全保偏光纤结构,系统具有较高的集成度和长期稳定性。将系统中积累的三阶色散与放大过程中引入的非线性啁啾相互补偿,通过控制展宽光纤的长度,优化了压缩后脉冲质量和宽度。同时分析了周期性光谱调制对放大输出的影响,通过优化保偏(2+1)×1光纤合束器的制作工艺,解决了其引起的周期性光谱调制问题,最终获得重复频率为111MHz,压缩后输出平均功率为9W,对应脉宽为260fs,单脉冲能量为81nJ,保偏比为13dB的高质量飞秒激光脉冲输出。 The common mode mode area ytterbium-doped polarization-maintaining double-clad fiber is used as the gain medium, and the full-polarization polarization fiber femtosecond laser amplification system is constructed by chirped pulse amplification technology. Due to full polarization fiber structure, the system has a high degree of integration and long-term stability. The third-order dispersion accumulated in the system and the nonlinear chirp introduced in the amplification process are mutually compensated. By controlling the length of the broadened optical fiber, the quality and width of the compressed pulse are optimized. At the same time, the influence of periodic spectral modulation on the amplified output is analyzed. By optimizing the fabrication process of the polarization maintaining (2 + 1) × 1 fiber combiner, the problem of periodic spectral modulation is solved. Finally, Compressed average output power of 9W, the corresponding pulse width of 260fs, single pulse energy of 81nJ, the polarization maintaining ratio of 13dB high-quality femtosecond laser pulse output.