Optically pumped GeSn lasers operating at 270 K with broad waveguide structures on Si

Lasing from direct bandgap group-IV GeSn alloys has opened a new venue for the development of Si- based monolithic laser. In this work, we demonstrate optically pumped GeSn lasers based on both ridge and planar waveguide structures. The near room temperature operation at 270 K was achieved with optically pumped edge-emitting devices. Moreover, due to the reduced side-wall surface recombination and improved thermal management, the 100 mu m wide ridge waveguide laser features a lower lasing threshold compared to other devices. The advance reported in this work, enabled by the material growth via an industry standard chemical vapor deposition reactor and low-cost commercially available precursors, is a major step forward toward Si-based mid-infrared sources for photonics integration.