2μm波长可调谐掺铥连续光纤激光器具有调谐范围宽、输出线宽窄和噪声低等特点, 在激光雷达、遥感、光通信、光谱分析、环境监测及激光医疗等领域具有重要应用, 近年来成为光纤激光技术领域的研究热点。文章首先介绍了可调谐光纤激光器中实现波长选择的各类光栅元件的基本结构及工作原理, 涉及到的光栅元件主要包括闪耀光栅、体布拉格光栅和光纤光栅; 其次重点阐述了基于光栅的可调谐掺铥连续光纤激光器在国内外的研究进展, 最后对其未来的发展趋势做出展望。

Tunable continuous-wave (CW) thulium-doped fiber lasers at 2μm are characteristics by widely tunable range, narrow linewidth and low noise. These lasers are widely used in the fields of laser lidar, remote sensing, optical communication, spectrum analysis, environmental monitoring, and laser medical system, etc, which have become a hot research topic in the fields of fiber laser technology. In this paper, the basic structures and principles of wavelength-tunable gratings in tunable fiber lasers are described. Main gratings include blazed gratings, volume Bragg gratings and fiber gratings. Then, the research progress of tunable CW thulium-doped fiber lasers based on the gratings at home and abroad is summarized. And the development tendency in the future is also discussed.