Soliton microresonator frequency combs

Optical frequency combs^1,2 provide equidistant markers in the IR, visible and UV and have become a pivotal tool for frequency metrology and are the underlying principle of optical atomic clocks, but are also finding use in other areas, such as broadband spectroscopy or low noise microwave generation. Development are underway to create chip-scale frequency comb sources[1] that are low power, compatible with wafer scale processing, exhibit microwave repetition rates, for applications that are airborne or in space. Such “micro-combs” are based on parametric frequency conversion of a continuous wave laser, and make use of dissipative Kerr soliton formation[2][3] [4] (DKS). Such dissipative Kerr solitons provide access to fully coherent and broadband combs with tailorable bandwidth. In this talk the Physics of dissipative solitons is reviewed, as discovered in crystalline resonators. Microcombs, give rise to a host of nonlinear dynamical phenomena, including Soliton Cherenkov radiation[5], breather solitons[6], soliton switching[7], to soliton crystals[8], and multi-soliton complexes. In addition soliton microcombs have been applied in massively parallel coherent communication[9], dual comb distance measurements[10], with record acquisition rate, and exhibit a bandwidth that can be extended to the biological imaging window. Soliton microcombs have the potential to advance timekeeping, and make frequency metrology ubiquitous.