窄线宽掺铒光纤激光器具有线宽窄、噪声低等优点, 在光纤通信、光纤传感、相干探测和合成等方面有广泛的应用。利用自行设计并制作的π相移光纤光栅和高反射率光纤布拉格光栅(FBG), 搭建了环形腔掺铒光纤激光器, 利用π相移光纤光栅的窄带滤波特性实现了1.5 μm波段的窄线宽掺铒光纤激光输出。当980 nm半导体激光抽运功率为5 W时, 激光输出功率为1.006 W, 光-光转换效率大于20%, 中心波长为1549.45 nm, 激光线宽为5.32 pm。输出光没有残余抽运光, 表明继续增加抽运光功率可以进一步提升激光功率。通过优化设计π相移光纤光栅的透射峰带宽、FBG的反射谱和激光腔结构, 有望实现高效、高功率的单纵模激光输出。

Erbium-doped fiber lasers have wide applications in fiber communication, fiber sensors, coherent detection and combination because of its narrow linewidth and low noise. An erbium-doped fiber laser with ring cavity is constructed by a self-designed π phase-shifted fiber grating and a high-reflective fiber Bragg grating (FBG), which can achieve narrow linewidth erbium-doped fiber laser output in 1.5 μm-band by utilizing the π phase-shifted fiber grating as a narrowband filter. When the pump power of 980 nm diode laser is 5 W, the laser output power is 1.006 W, the optical to optical efficiency is more than 20%, and the central wavelength is 1549.45 nm with laser linewidth of 5.32 pm. The output light is without residual pump, which indicates that the laser power can be further increased by increasing pump power. High-efficiency, high power, single-longitudinal-mode laser can be achieved by optimizing the bandwidth of transmission peak of π phase-shifted fiber grating, the reflectance spectrum of FBG, and the structure of the laser cavity.