Nanowire Lasing With SiN Microring Resonator

ABSTRACT We report on‐chip room temperature lasing of a nanowire (NW) embedded into a silicon nitride (SiN) microring resonator, where the NW functions as the gain medium whilst the microring provides optical feedback. Owing to the high‐quality factor of the hybrid microring, the microring‐assisted NW laser exhibits a reduction of lasing threshold to 25.8% and a linewidth narrowing to 11.2% at 1.1 × P th (lasing threshold), compared to the stand‐alone NW laser. Additionally, since the gain medium is only provided by the NW and occupies only a minor portion of the microring resonator, common issues in stand‐alone NW lasers, such as wavelength drift and linewidth broadening under increased excitation power, are effectively mitigated. The microring‐assisted NW laser offers a viable on‐chip light source for SiN photonics, as further demonstrated by coupling the laser output to a bus‐waveguide.