1D photonic crystal direct bandgap GeSn-on-insulator laser

GeSn alloys have been regarded as a potential lasing material for complementary metal–oxide–semiconductor-compatible light source. Despite their remarkable progress, all lasers reported to date large device footprints and active areas, which prevent the realization of densely integrated on-chip operating at low power consumption. Here, we present 1D photonic crystal nanobeam with very small footprint 7 ?m2 compact area ?1.2 on high-quality GeSn-on-insulator substrate. We also report that improved directness in our strain-free leads lower threshold density higher temperature compared compressive strained counterparts. The laser is ?18.2 kW cm?2 4 K, significantly than unreleased (?38.4 K). Lasing persists up 90 whereas shows quenching 70 K. Our demonstration offers an avenue toward developing practical group-IV sources high-density integration