Monolithic integration and epitaxial gain control of GaAs-based nanowire lasers on Si

Here, we present our recent highlights on monolithically integrated GaAs-nanowire lasers on silicon and further demonstrate capabilities in epitaxial gain control to tune threshold power density and lasing wavelength. Importantly, the investigated NW lasers reveal high spontaneous emission coupling factors (beta-factor) of 0.2, and ultrafast temporal emission down to 250 GHz. Introduction of coaxial multiple-quantum wells in the NW lasers allows to tune threshold power density, opening a gateway for advanced epitaxial gain control. Ultimately, we also demonstrate continuous-wave lasing under optical excitation of the GaAs-nanowire lasers with very sharp emission linewidths, lower required pump power and negligible heating effects.