Soliton-comb solutions for fiber-based bottle microresonators

We predict a stable generation of optical solitons and related low-repetition frequency combs in high-Q fiber-based bottle resonators of different shapes. The modal localization effect is controlled by the shaping of the fiber radius. The solitons consist of axial resonator modes, belong to a single azimuth modal number, and possess anomalously small velocities. They are remarkably similar to each other for different resonator shapes and strongly different from conventional azimuth soliton-comb states: instead of the modal dispersion, the soliton width and amplitude are controlled by the critical self-focusing power.