Two-dimensional nonlinear modes and frequency combs in bottle microresonators

TL;DR

This paper theoretically explores frequency comb generation in bottle microresonators, revealing the formation of 2D solitons and complex spatio-temporal patterns due to azimuthal and axial nonlinear mode interactions.

Contribution

It introduces a novel analysis of 2D nonlinear modes and solitons in bottle microresonators considering both azimuthal and axial degrees of freedom.

Findings

Identification of discrete axial nonlinear modes bifurcating from linear spectrum.

Existence of stable and unstable 2D solitons depending on pump detuning.

Observation of complex dynamics including breathers and collapse-like evolution.

Abstract

We investigate theoretically frequency comb generation in a bottle microresonator accounting for the azimuthal and axial degrees of freedom. We first identify a discrete set of the axial nonlinear modes of a bottle microresonator that appear as tilted resonances bifurcating from the spectrum of linear axial modes. We then study azimuthal modulational instability of these modes and show that families of 2D soliton states localized both azimuthally and axially bifurcate from them at critical pump frequencies. Depending on detuning, 2D solitons can be either stable, or form persistent breathers, chaotic spatio-temporal patterns, or exhibit collapse-like evolution.