On-chip room-temperature CW lasing from a III–V nanowire integrated with a Si photonic crystal platform

We report the demonstration of continuous-wave (CW) lasing at room temperature from a III–V semiconductor nanowire integrated into a Si photonic crystal (PhC) cavity. Previous hybrid nanowire lasers [M. Takiguchi et al., APL Photonics 2, 046106 (2017)], which typically feature circular nanowire-cross sections, suffer from a weak optical confinement, preventing CW lasing under ambient conditions. To overcome this limitation, we fabricated nanowires with rectangular cross sections via dry etching and integrated them into the air trenches of Si PhC cavities formed using atomic force microscope tips. This configuration forms a hybrid photonic crystal cavity with an improved optical confinement. As a result, we achieved room-temperature CW oscillation from a single nanowire, representing a significant step toward on-chip nanophotonic light sources. This unique in-plane integration of the nanolaser in the same plane as the Si slab, rather than on top of the substrate, will contribute to the development of compact, scalable, and complementary metal–oxide–semiconductor-compatible photonic circuits.