Study on the detuning-dependent properties of a temporal dissipative Kerr soliton in an optical microresonator

Temporal dissipative Kerr solitons in a continuous-wave laser-driven nonlinear optical microresonator enable compact, high-repetition rate sources of ultrashort pulses and coherent broadband optical frequency combs. A central parameter in the soliton formation process, is the effective detuning of the pump laser to the thermally- and Kerr-shifted cavity resonance, which, together with the free spectral range and dispersion, governs the soliton pulse duration. Here, we introduce a technique to probe, stabilize, and control the effective detuning of a driven nonlinear crystalline resonator while monitoring the dissipative Kerr soliton properties, which enables to study the detuning-dependent soliton properties and accurate comparisons of the theoretical predictions with experiments. We demonstrate that the experimentally measured relation between detuning and soliton duration deviates by less than 1% from the analytical solution, demonstrating its excellent predictive power. In contrast, avoided mode crossings, induced by a linear mode coupling in the resonator mode spectrum, are found to alter the comb profile, leading to a detuning-dependent enhancement or suppression of specific comb lines. This causes deviations from the expected comb power evolution and is shown to induce a detuning-dependent recoil on the soliton, which leads to a modification in the pulse repetition rate. The presented results provide unprecedented precision in the verification of the analytical solutions of such solitons, and provide insights into the detuning dynamics of this class of solitons.