Silicon photonics is a rapidly developing technology that promises to revolutionize the way we communicate, compute and sense the world1–6. However, the lack of highly scalable, native complementary metal–oxide–semiconductor (CMOS)-integrated light sources is one of the main factors hampering its widespread adoption. Despite considerable progress in hybrid and heterogeneous integration of III–V light sources on silicon7–12, monolithic integration by direct epitaxy of III–V materials remains the pinnacle of cost-effective on-chip light sources. Here we report the electrically driven gallium arsenide (GaAs)-based laser diodes fully fabricated on 300-mm Si wafers in a CMOS pilot manufacturing line based on a new integration approach, nano-ridge engineering. GaAs nano-ridge waveguides with embedded p–i–n diodes and InGaAs quantum wells are grown at high quality on a wafer scale. Room-temperature continuous-wave lasing is demonstrated at wavelengths around 1,020 nm in more than 300 devices across a wafer, with threshold currents as low as 5 mA, output powers beyond 1 mW, laser linewidths down to 46 MHz and laser operation up to 55 °C. These results illustrate the potential of the III–V/Si nano-ridge engineering concept for the monolithic integration of laser diodes in a Si photonics platform, enabling future cost-sensitive high-volume applications in optical sensing, interconnects and beyond.
