报道了一种基于反射式石墨烯可饱和吸收镜锁模的全保偏掺铒光纤激光器。分别使用单层和十层石墨烯作为可饱和吸收器件, 通过全保偏结构, 避免了外界环境对腔内偏振态的影响, 获得了高稳定性、高偏振度、易自启动的锁模脉冲输出, 脉冲宽度分别为697 fs和502 fs。实验表明, 十层石墨烯相比于单层石墨烯能够获得更窄的脉冲宽度, 更高的峰值功率, 具有好的锁模效果。研究同时发现, 经十层石墨烯锁模, 进一步提高泵浦功率, 可在全保偏光纤腔中获得重复频率62.94 MHz的二阶谐波锁模脉冲输出。并通过非线性薛定谔方程对谐波锁模产生的机理进行了分析。这种基于反射式可饱和吸收镜的全保偏锁模光纤激光器有望成为实现基频锁模与谐波锁模可切换的单偏振激光源。

An all-polarization-maintaining erbium-doped fiber laser mode-locked by graphene saturable absorber mirror was reported. The laser with monolayer and ten-layer graphene as saturable absorbers devices avoided the influence of environment on the intracavity polarization and generates high stability, high degree of polarization and self starting mode-locked pulse output with pulse width of 697 fs and 502 fs. Compared to single layer graphene, the ten layers graphene can obtain shorter pulse width, higher peak power and better mode locking effect. While the pump power increases, a two harmonic mode-locked pulse with 62.94 MHz repetition frequency can be generated. The mechanism of harmonic mode locking was analyzed by nonlinear Schrodinger equation. The mode-locking laser cavity based on the reflection mirror was expected to be the excellent single polarization femtosecond fiber laser source which can be switched between the fundamental frequency and the two harmonic.