Generation of high-speed laser pulses is essential for sustaining today’s global, hyper-connected society. One approach for achieving high spectral and temporal purity is to combine optical nonlinear materials with spectral filtering devices. In this work, a graphene-coated microresonator integrates a nonlinear material and a spectral filtering platform into a single device, creating a tunable GHz repetition rate mode-locked fiber laser. The graphene is directly synthesized on the non-planar surface of microresonator, resulting in a uniform, conformal coating with minimal optical loss in the device. The whispering gallery modes of the resonator filter the propagating modes, and the remaining modes from the interaction with graphene lock their relative phases to form short pulses at an elevated repetition rate relying on inter-modal spectral distance. Additionally, by leveraging the photo-thermal effect, all-optical tuning of the repetition rate is demonstrated. With optimized device parameters, repetition rates of 150 GHz and tuning of 6.1 GHz are achieved.

高速激光脉冲的产生对于维持当今全球高度互联的社会至关重要。实现高光谱和时间纯度的一种方法是将光学非线性材料与光谱滤波装置相结合。在这项工作中，石墨烯涂层微谐振器将非线性材料和光谱滤波平台集成到单个设备中，从而创建了可调谐 GHz 重复率锁模光纤激光器。石墨烯直接合成在微谐振器的非平面表面上，从而形成均匀的保形涂层，并且器件中的光学损耗最小。谐振器的回音壁模式过滤传播模式，并且与石墨烯相互作用的剩余模式锁定其相对相位，从而依赖于模间光谱距离以较高的重复率形成短脉冲。此外，通过利用光热效应，演示了重复率的全光学调谐。通过优化的器件参数，可实现 150 GHz 的重复率和 6.1 GHz 的调谐。