A high-power and narrow-linewidth Er, Yb co-doped fiber laser is demonstrated by using two serially-paired volume Bragg gratings. A maximum output power of 19.4 W at 1545.3 nm with a full-width at half-maximum linewidth of <～38 pm is obtained for 65.3 W of launched pump power, corresponding to a slope efficiency of 30.1% with respect to launched pump power.

High power and widely wavelength tunable operation of cladding-pumped Er,Yb fiber lasers are demonstrated with operating wavelength covering the whole C- and L-band and spectral linewidth FWHM of less than ～0.3 nm over the whole tuning range. Wavelength tuning is realized by the use of an external cavity containing a volume Bragg grating with peak reflectivity >99% at 1650 nm. A tuning range of 45.5 nm from 1533.5 to 1579 nm is obtained for a 7 m Er,Yb fiber. Output power up to 23.8 W is generated at 1565.7 nm for 142.4 W of launched pump power. Using a longer gain fiber of 17 m, the operating wavelength shifted toward the long wavelength side, covering a tuning range of over 67 nm from 1556.7 to 1624.4 nm. A maximum output power of 24.9 W at 1567.5 nm is achieved for the launched pump power of 126.5 W.

具有高光束质量的高重复频率、窄脉冲的光纤激光器种子源在主振荡功率放大(MOPA)型高功率脉冲光纤激光器中扮演着重要的角色。报道了一种基于高速激光二极管（LD）直接调制的、多级光纤放大的高重复频率线偏振Yb脉冲光纤激光器的种子源研制工作。通过自行研制重复频率和脉冲宽度可调、工作性能稳定的高速驱动电源，直接驱动工作波长为1064 nm的尾纤输出半导体激光器,并采用两级级联的Yb光纤放大器进行放大，实现了重复频率在5 kHz~10 MHz间可调、脉冲宽度在20~200 ns间可调、工作波长为1064 nm的线偏振激光输出。在重复频率200 kHz、脉宽为100 ns时，获得平均输出功率800 mW，偏振抑制比超过25 dB，光束质量因子接近1的近衍射极限线偏振脉冲激光输出，可以作为高重复频率脉冲激光种子，经过后端放大能获得更高功率的脉冲激光输出。

报道了一台全光纤结构主振荡功率放大(MOPA)型掺镱脉冲光纤激光器。种子源是工作波长为1064 nm的声光调Q光纤激光器, 可以获得重复频率在20～50 kHz间可调、平均输出功率约2 W的随机偏振脉冲种子激光。以大直径保偏(PM)光纤作为增益介质, 在6个单管功率10 W, 波长为915 nm的半导体激光器抽运下, 种子激光经过一级放大最终获得平均输出功率23.5 W, 脉冲宽度约为30 ns, 偏振抑制比超过10 dB, 光束质量因子M2为1.36的线偏振单模脉冲激光输出。讨论了大直径保偏光纤与种子激光输出光纤的模场不匹配性对输出激光的光束质量和光谱特性的影响。