Dispersive wave control in soliton fiber lasers via online high-order dispersion engineering

Ultrafast fiber lasers generating temporal solitary pulses have found important applications in numerous fields. Circulating within the laser cavity, such solitons would feature dispersive wave generation due to the perturbation of cavity parameters. While Kelly sidebands have been widely recognized as dispersive waves in fiber lasers due to an intrinsic periodic loss perturbation, optical Cherenkov radiation-an alternative dispersive wave regime that is enabled by high-order dispersion-has been less explored. In this Letter, we demonstrate a broad control of dispersive waves in an ultrafast fiber laser via online dispersion engineering, which enables precise tuning of both the Cherenkov radiation and Kelly sidebands and enables a transition in between via manipulation of third- and fourth-order dispersion (TOD and FOD). Furthermore, we identify a retrieval method for tracing cavity high-order dispersion from frequencies of dispersive waves, which has been traditionally challenging. Our findings would not only help gain in-depth understanding of cavity soliton dynamics but may also contribute to advanced design of ultrafast lasers.