A compact electrically-pumped hybrid silicon microring laser

A compact electrically-pumped hybrid silicon microring laser is realized on a hybrid silicon platform. A simplified, self-aligned, deep-etch process is developed to result in low-loss resonator with a high quality factor Q≫15,000. Small footprint (resonator diameter=50 µm), electrical and optical losses all contribute to lasing threshold as low as 5.4 mA and up to 65 °C operation temperature in continuous-wave (cw) mode. Outcoupling- and bus waveguide width-dependent studies are conducted for optimizing device structure. A simple qualitative study in current-voltage (IV) characteristic shows that dry etching through active region leads to ≪3× more leakage current at the same reverse bias than wet etch counterpart. It indicates a relatively good interface with tolerable surface recombination from deep dry etch. The spectrum is single mode with large extinction ratio (≫40 dB) and small linewidth (≪0.04 nm) observed. The unique bistability operation in ring resonator structure is also demonstrated.