Influence of straight waveguide facet reflectivity on the dynamics of semiconductor microring lasers

摘要

A multimode model based on the rate equation approximation is presented in order to simulate the mode dynamics and noise characteristics of semiconductor microring lasers. The effect of straight waveguide facet residual reflectivity is studied in detail. A complete characterization is performed including calculated optical mode spectra, time traces and relative intensity noise (RIN) spectra. Different operation regimes are demonstrated, stable multimode, stable single mode, and hopping multimode dependent on the injection current and the straight waveguide reflectivity. An expansion of the stable single mode operation regime is observed up to higher injection currents with a respective suppression of the mode-hopping regime, for a power reflectivity ratio of -30dB for both facets. Moreover, the use of different reflectivities for each facet at appropriate values promotes unidirectional operation.