Multiple nonlinear resonances and frequency combs in bottle microresonators

Abstract

We introduce the generalized Lugiato-Lefever equation describing nonlinear effects in the bottle microresonators. We demonstrate that the nonlinear modes of these resonators can form multiple coexisting and overlapping nonlinear resonances and that their instabilities lead to the generation of the low repetition rate frequency combs.

Optical bottle microresonators

“…The experimental results [70] suggest that the optical frequency comb with the predetermined repetition rate and central frequency can be generated by the appropriately designed BMR. The numerical simulations of BMR frequency comb generators [32][33][34][35] reviewed in Section 2.6 support this prediction. The SNAP technology, which allows for the ultraprecise fabrication of such microresonators, makes their demonstration feasible in the nearest future.…”

“…The paper starts with the review of the BMR theory (Section 2), which includes BMR spectral properties [11,29,30], slow WGM propagation along BMRs, theory of Surface Nanoscale Axial Photonics (SNAP) BMRs [20,21,25], theory of resonant transmission of light through BMR microresonators coupled to transverse waveguides (microfibers) [25], theory of nonstationary WGMs in BMRs [31], and theory of nonlinear BMRs [32][33][34][35][36]. Next, in Section 3, the fabrication methods of BMRs including melting of optical fibers, fiber annealing in SNAP technology, rolling of semiconductor bilayers, solidifying of a UV-curable adhesive, local heating, femtosecond laser inscription, and others are reviewed [18,23,.…”

Emerging material systems for integrated optical Kerr frequency combs

“…Dispersion of the silica microbubbles are engineered by modifying the geometry parameters and Kerr frequency combs are generated from these devices. [321,[344][345][346] However, while the toroidal cavities are based on a lithographically defined microdisk, the final fabrication step involves a laser-induced reflow process to remove any residual surface roughness. [121] This step enables ultra-high-Q factors to be readily achievable, but it makes the device diameter even harder to control than when hand-polished methods are used.…”

Comb of high‐Q Resonances in a Compact Photonic Cavity

“…The question which is addressed here is how to create a comb of resonances starting from the fundamental order mode in the smallest possible optical cavity, such to maximize the energy‐efficiency of parametric interactions. Frequency combs starting from the (axial) fundamental order mode have been discussed theoretically in the context of the surface axial photonics . Such axial resonators are shaped along the axial direction to support higher order whispering gallery modes.…”

“…Such axial resonators are shaped along the axial direction to support higher order whispering gallery modes. It is shown there that an effective parabolic potential can be obtained, resulting into the Gauss‐Hermite modes of a quantum mechanical oscillator, hence into rigorously equi‐spaced resonances. The size of this resonator, however, is considerable.…”