介绍了一种多环形腔结构(MRC)的单纵模(SLM)掺铒光纤激光器(EDFL)。这种激光器通过在主环形腔中插入充当模式滤波器的三个长度不等的无源次级环形腔, 并结合腔内光纤布拉格光栅(FBG)形成多环形腔掺铒光纤激光器结构, 多环形谐振腔可保证激光器的单纵模输出。讨论了使激光器运行在单纵模状态的谐振腔理论。同时, 为了提高系统输出的频率稳定性, 采用外光注入方法有效地抑制了模式跳变和拍噪声, 改善了输出谱特性。实验得到在1550.225 nm处输出功率约3.6 dBm, 信噪比(SNR)>35 dB的单纵模输出光, 且测得线宽小于500 Hz。

A single longitudinal mode(SLM) erbium-doped fiber laser (EDFL) with multiple ring cavities (MRCs) is proposed and experimentally demonstrated. The EDFL is structured by insertion of three different short passive subring cavities, which serve as mode filters, into the main cavity, and it is combined with a fiber Bragg grating (FBG), the MRCs resonator can make SLM lasing. The resonant theory of MRCs for SLM operation is discussed. At the same time, in order to stabilize, the frequency of output laser, external light injection techniques are employed to effectively suppress the mode jump and beat noise. Output power of 3.6 dBm and signal-noise-ratio (SNR) larger than 35 dB at 1550.225 nm, and linewidth less than 500 Hz are achieved for this laser.