光纤饱和吸收体稳频窄线宽光纤激光器

Frequency stabilized narrow linewidth fiber laser by fiber saturable absorber

结合光纤饱和吸收体与光纤光栅法布里-珀罗标准具,研制出了全光纤结构1550nm单频窄线宽掺铒光纤环形激光器。采用两个976nm激光二极管双向抽运作为抽运源,高掺杂浓度铒光纤作为增益介质,以行波腔消除空间烧孔效应,利用光纤光栅法布里-珀罗标准具窄带选模特性,以10m长低掺铒光纤饱和吸收体稳频,得到了十分稳定的窄线宽激光输出。激光器抽运阈值功率21mW,在抽运光功率为145mW时输出光功率39mW,斜率效率30%,信噪比大于50dB。采用延迟自外差方法精确测量光纤激光器线宽小于10kHz。

Single frequency 1550nm Erbium-doped fiber ring laser was demonstrated by introducing fiber saturable absorber and passive fiber Bragg grating Fabry-Perot etalon in laser cavity. As narrow bandwidth filter, the passive fiber Bragg grating Fabry,Perot etalon discriminated and selected laser longitudinal modes efficiently. Spatial hole burning effect was eliminated by traveling-wave cavity. Lasing frequency was stabilized by using 10m low concentration Erbium-doped fiber as saturable absorber. Stable single frequency 1550nm laser was acquired. High concentration Erbium-doped fiber was adopted as gain medium in the fiber laser. Pumped by two 976um laser Diodes, the fiber laser has a threshold of 21 mW. Laser output power is 39mW at 1550nm with a pump power of 145mW, and the corresponding slope efficiency is 30%. The SNR is larger than 50dB. The laser linewidth is less than 10kHz, measured by the delayed self-heterodyne method with 10km single mode fiber.