Electrically pumped 1.5  μm InP-based quantum dot microring lasers directly grown on (001) Si

Directly grown quantum dot (QD) lasers on silicon are appealing for monolithic integration of photonic circuits from a technoeconomic perspective. In this Letter, we report miniaturization of these Si-based lasers employing high-quality whispering-gallery mode microresonators. Based on previously developed InAs/InAlGaAs QDs on the complementary metal-oxide-semiconductor-standard (001) Si platform and optimized device implementation techniques, on-chip electrically pumped InP-based QD microring lasers (MRLs) on Si are successfully realized for the first time. Room-temperature pulsed lasing in the 1.5 μm wavelength band, with a threshold of 50 mA, is measured for 50-μm-diameter MRLs. Lasing up to 70°C is achieved with a characteristic temperature of 51.5 K.