Theoretical analysis of the electromagnetic field inside an anomalous-dispersion microresonator under synthetical pump

We study the spatiotemporal evolution of the electromagnetic field inside a microresonator showing an anomalous dispersion at the pump wavelength by using the normalized Lugiato-Lefever equation. Unlike the traditional single continuous wave (CW) pumping, an additional pump source consisting of periodical pulse train with variable repetition rate is adopted. The influences of the microresonator properties and the pump parameters on the field evolution and the electromagnetic field profile are analyzed. The simulation results indicate that, in the anomalous dispersion regime, both increases of the input pulse amplitude and the repetition frequency can result in the field profiles consisting of multiple peaks. A series of equidistant pulses can also be obtained by increasing the CW pump power. In addition, we find that a large physical detuning between the pump laser carrier and the cavity resonance frequency also causes the splitting of the inside field.