Modulational instability and solitons in microring resonators with localized pump

Abstract

Nonlinear effects in cavities and microresonators attract nowadays considerable attention, mainly because they allow generation of equidistant optical frequency combs [1] that are desirable for a number of applications in diverse areas of science. In proper regime, phases of different comb lines may be synchronized leading to formation of stationary soliton states moving along the microresonator. Such bright microresonator solitons were observed in [2]. Microresonators possess intrinsic losses, hence external pump (forcing) is required to maintain essentially dissipative solitons in such systems. In all previous studies the pump was assumed to be uniformly distributed across microresonator, while in practice it is spatially localized (as well as losses that may be locally enhanced around contact region with external wire providing pump). In this presentation we consider modulational instability and formation of solitons in microresonators with localized pump and losses, that drastically enrich the spectrum of resonances and may lead to coexistence of solitons with different amplitudes in the strong driving limit.