High-power and narrow-linewidth semiconductor laser with silicon nitride microring

Based on a high power InGAsP distributed feedback (DFB) semiconductor laser coupling with an ultra-high-Q silicon nitride microring, we proposed a hybrid integration semiconductor laser scheme for realizing high power and narrow linewidth. For such a scheme, the high power DFB laser serves as the light source, whose output is efficiently coupled into the input waveguide port of ultra-high-Q silicon nitride microring through a silicon lens. Under the optical feedback provided by the Rayleigh scattering in the inhomogeneity silicon nitride microring, the laser may be driven into the self-injected locking state, under which the lasing linewidth can be obviously narrowed. The experimental results demonstrate that, adopting such a hybrid integration scheme, the lasing linewidth can be narrowed to 10 kHz and meanwhile the output power is maintained at the level of 20 mW. The hybrid integration semiconductor lasers have application prospects in some fields simultaneously requiring high coherence and high power, such as LiDAR and long-distance coherence communication.