A Ge-on-Si laser operating at room temperature

Monolithic lasers on Si are ideal for high volume and large-scale electronic-photonic integration. Ge is an interesting candidate due to its pseudo-direct gap properties and compatibility with Si complementary metal oxide semiconductor (CMOS) technology. Recently we have demonstrated room temperature photoluminescence, electroluminescence and optical gain from the direct gap transition of band-engineered Ge-on-Si using tensile strain and n-type doping. Here we report the first experimental observation of lasing from the direct gap transition of Ge-on-Si at room temperature using an edge emitting waveguide device. The emission exhibited a gain spectrum of 1590-1610 nm, line narrowing and polarization evolution from a mixed TE/TM to predominantly TE with increasing gain, and a clear threshold behavior. OCIS codes: 130.5990, 160.3380, 250.5960