搭建了基于非线性放大环形镜的全保偏掺铒光纤激光器,它可为光梳系统在室外环境中的应用提供稳定运行的光学振荡源。在实验上,通过两级光学预放大及高非线性光纤获得了1000~2300 nm的超连续谱,采用共线型f-2f干涉仪检测到的载波包络偏移频率f0的信噪比高达35 dB。研究了腔内净色散和f0线宽的关系,并将自由运转状态下的f0线宽窄化至5 kHz。将光梳系统的主要参数(重复频率fr和载波包络偏移频率f0)溯源至同一台铷原子钟,锁定后所测标准偏差分别为780 μHz和308 mHz。该光纤光梳系统具有集成度高、体积小的特点。

An all polarization-maintaining fiber laser is established based on a nonlinear amplifying loop mirror, and thus a stable optical oscillator source is applied to an optical comb system which works outdoors. In this experiment, supercontinuum covering from 1000 nm to 2300 nm is produced by using two-level optical preamplification and high nonlinear fibers. The optimal signal-to-noise ratio of carrier-envelope offset frequency f₀ detected by the collinear f-2f interferometer is 35 dB. Furthermore, the relationship between the net cavity dispersion and the linewidth of f₀ is investigated. The narrowest linewidth of f₀ in the free-running mode is narrowed to 5 kHz. Finally, the repetition rate f_r and f₀ are both phase-locked to a rubidium atomic clock. The standard deviations for f_r and f₀ are 780 μHz and 308 mHz, respectively. The fiber optic comb system guarantees compact size and excellent integration level.