重复频率锁定的783 nm飞秒光纤激光器研制

设计并搭建了重复频率长时精确锁定的783 nm飞秒光纤激光器。该激光器基于全保偏非线性干涉环镜(NALM)，实现掺铒光纤振荡器锁模脉冲输出，由与脉冲分离器级联的环境稳定掺铒光纤双级放大器进行功率放大，实现了平均功率1.30 W、脉冲宽度130 fs、重复频率77.1 MHz、1560 nm脉冲输出；通过周期极化铌酸锂(PPLN)光学晶体倍频，获得了平均功率为0.52 W、脉冲宽度为140 fs、783 nm脉冲输出。通过重复频率监测及锁相环技术，进一步将掺铒光纤振荡器的重复频率溯源至参考铷原子钟，12 h内频率抖动峰-峰值为5 mHz、标准偏差为1.2 mHz。该激光器系统具有稳定性高、集成度高、体积小的特点。

Development of a 783 nm femtosecond fiber laser with repetition frequency locking

A 783 nm femtosecond fiber laser with long repetition rate was designed and constructed. The laser was based on the amplifying loop mirror mode-locked erbium-doped fiber oscillator and the environment-stable erbium-doped fiber double-stage amplifier cascaded by pulse separator. An average power of 1.3 W, pulse width of 130 fs, repetition rate of 77.1 MHz, and 1560 nm pulse output are achieved. By frequency doubling using periodically poled lithium-niobate, an average power of 0.5 W, a pulse width of 140 fs and a pulse output of 783 nm were obtained. Furthermore, the repetition frequency of erbium-doped fiber oscillator was traced to the rubidium atomic clock by repetition frequency monitoring and phase-locked loop technology. The peak value of frequency jitter is 5 mHz and the standard deviation is 1.2 mHz within 12 hours. The laser system has the characteristics of high stability, high integration and small volume.