将单层石墨烯覆盖在拉锥光纤上, 光通过倏逝场和石墨烯相互作用实现锁模脉冲输出。当抽运功率调到阈值230 mW时, 可以实现自启动的锁模脉冲输出; 将抽运功率固定在300 mW处, 调节偏振控制器可实现一个孤子束中包含2~6个脉冲的可控脉冲数输出; 将抽运功率固定在450 mW处, 调节偏振控制器可实现不同阶次的谐波锁模, 最高实现117阶谐波锁模, 此时脉冲重复频率高达2.412 GHz。

A section of graphene film is transferred on the tapered fiber and the light interacts with graphene by the evanescent field so as to generate the mode-locked pulse. When the pump power is transferred to the threshold of 230 mW, the self-staring mode-locked pulse can be realized. Fixing the pump power at 300 mW, soliton bundles with controlled 2-6 sub-pulses are generated by adjusting the polarization controller. Fixing the pump power at 450 mW, different order harmonic mode-locked pulses can be achieved by adjusting the polarization controller. The highest order of harmonic mode-locked pulse is 117, and the corresponding pulse repetition frequency is 2.412 GHz.