Broadband microcomb generation from a zero-dispersion fiber Fabry-Pérot microresonator

Microcombs have exhibited outstanding potential in the fields of optical frequency synthesizer, atomic clock, lidar, etc. To achieve a fully stabilized optical frequency comb, the microcombs should simultaneously have a nearly octave spectrum for self-referenced locking and a relatively small comb line spacing so that the beating frequency can be located in a comfortable photodetection bandwidth, e.g., 10 GHz. Unfortunately, it is still challenging for microcombs based on integrated microresonators, mainly due to the limitation on waveguide loss and dispersion control. Moreover, it is also highly desired that the microcombs can be stabilized in a simple way rather than complicated control.