超低功率自启动且色散平衡的光纤锁模激光器

Ultra-Low Power Self-Starting and Dispersion-Balanced Fiber Mode-Locked Laser

低腔损、低自启动功率、稳定且色散平衡的光纤激光器是实现后续放大、压缩和外场实验应用的必要条件。结合理论分析和数值模拟方法,详细阐述了移相器在激光器自启动中的关键作用,以及增益光纤掺杂浓度与激光启动阈值的关系,进而得出了降低自启阈值的条件。基于理论结果,利用光纤非线性增益环形镜结构,搭建了腔损极低且近零色散的锁模激光器振荡器,实现了60 mW的超低自启动功率和最低30 mW的稳定工作功耗,验证了理论结果。为适应更多实验环境,搭建包含可调波片的分离器件结构的非线性放大环镜,来确保激光器能够自启动,并加入压电陶瓷和光电调制器,使该激光器具备稳定至国际时频标准的能力。该激光器的自启动功率为160 mW,维持锁定功率仅为16 mW。

A fiber laser with low cavity loss,low self-starting power,stability,and dispersion-balanced performance is required for subsequent amplification,self-compression,and external field experimental applications.Therefore,this study conducts an in-depth investigation of the critical role of the phase shifter in laser self-starting using theoretical analysis and numerical simulation methods.Additionally,the relationship between the gain fiber doping concentration and the laser starting threshold is established.Based on theoretical results,a low-loss and near-zero dispersion fiber-laser oscillator was constructed using a nonlinear amplified loop mirror.The proposed oscillator achieves an ultra-low self-starting power of 60 mW and a minimum stable operating power consumption of 30 mW,thus,validating the theoretical results.To adapt to more experimental environments,a nonlinear amplification loop mirror with a separated device structure containing a variable wave plate was constructed to ensure the self-starting capability of the laser.Additionally,a piezoelectric ceramic and an optical modulator were added for laser stabilization according to the international time and frequency standard.The laser self-starting power is 160 mW with only 16 mW maintenance power required.