中文摘要：

设计并制造了一种基于二波混频的高功率单频窄线宽光纤激光器。激光器采用长线形腔结构，以Er^3＋／Yb^3＋双包层光纤作为增益介质，利用输出信号光分束反馈注入，与腔内振荡激光混频干涉，形成分布的增益光栅与折射率光栅共同作用选模，获得稳定的1550．63nm单频高功率激光输出。在975nm多模激光二极管（LD）抽运下，激光器抽运阈值光功率为356mW。当抽运光功率为3．1W时，激光器输出信号光功率为653．7mw，对应的光-光转换效率为21．1％，斜率效率为24．6％，信噪比大于50dB。用延时自外差方法测量激光器输出的3dB光谱线宽为5．0kHz。

英文摘要：

A novel high-power single-frequency narrow linewidth fiber laser with long linear laser cavity is designed and manufactured by using nonlinear two-wave mixing. The distributed gain gratings and refractive index gratings, which are generated by interfering between the feedback injecting light from the part of output light and the lasing light in intra-cavity, are used to select longitudinal modes efficiently and ensure stable single-frequency operation. A segment Er^3＋/Yb^3＋ co-doped double cladding fiber is used as gain medium and is pumped by multi-modes laser diodes （LD） with wavelength of 975 nm, and then stable high-power single- frequency laser at 1 550.63 nm is acquired. The fiber laser exhibits a 356 mW threshold and laser output power is 653.7 mW for a pump power of 3. 1 W. Optical-optical efficiency is 21. 1% , slope efficiency is 24.6% and signal-to-noise ratio （SNR） is large than 50 dB. The 3 dB linewidth of the fiber laser is about 5.0 kHz, which is measured by the delayed self-beterodyne method with 40 km delayed fiber.