Monolithic integration of high-performance semiconductor lasers on silicon enables wafer-scale optical interconnects within photonic integrated circuits on a silicon manufacturing platform. III−V quantum dot (QD) lasers on silicon stand out for their better device performances and reliability. QD lasers grown on III−V substrates have been integrated by wafer-bonding techniques with high quality. Direct growth of QD lasers on silicon offers an alluring alternative, using widely available large-area silicon substrates. However, to date, notable achievements have been reported only in InAs/GaAs lasers emitting at 1.3 μm, while 1.55 μm InAs/InP QD lasers on silicon remain in uncharted territory. Here we demonstrate the first 1.55 μm band InAs/InAlGaAs quantum dot microdisk lasers epitaxially grown on (001) silicon substrates. The lasing threshold for the seven-layer quantum dot microdisk laser at liquid-helium temperature is 1.6 mW under continuous optical pumping. The observed lasing is attributed to a unique combination of the high-quality QDs, small mode volume, and smooth sidewall of the microdisk structure and a welldeveloped InP buffer incorporating quantum dots as dislocation filters. These results thus mark a major step toward an integrated III−V-on-silicon photonics platform.

Miniaturized laser sources can benefit a wide variety of applications ranging from on-chip optical communications and data processing, to biological sensing. There is a tremendous interest in integrating these lasers with rapidly advancing silicon photonics, aiming to provide the combined strength of the optoelectronic integrated circuits and existing large-volume, low-cost silicon-based manufacturing foundries. Using III-V quantum dots as the active medium has been proven to lower power consumption and improve device temperature stability. Here, we demonstrate room-temperature InAs/InAlGaAs quantum-dot subwavelength microdisk lasers epitaxially grown on (001) Si, with a lasing wavelength of 1563 nm, an ultralow-threshold of 2.73 μW, and lasing up to 60 °C under pulsed optical pumping. This result unambiguously offers a promising path towards large-scale integration of cost-effective and energy-efficient silicon-based long-wavelength lasers.

Electrically pumped on-chip C-band lasers provide additional flexibility for silicon photonics in the design of optoelectronic circuits. III–V quantum dots, benefiting from their superior optical properties and enhanced tolerance to defects, have become the active medium of choice for practical light sources monolithically grown on Si. To fully explore the potentials of integrated lasers for silicon photonics in telecommunications and datacenters, we report the realization of 1.5 μm room-temperature electrically pumped III–V quantum dot lasers epitaxially grown on complementary metal-oxide-semiconductor (CMOS)-standard (001) Si substrates without offcut. A threshold current density of 1.6 kA/cm2, a total output power exceeding 110 mW, and operation up to 80 °C under pulsed current injection have been achieved. These results arose from applying our well-developed InAs/InAlGaAs/InP QDs on low-defect-density InP-on-Si templates utilizing nano-patterned V-grooved (001) Si and InGaAs/InP dislocation filters. This demonstration marks a major advancement for future monolithic photonic integration on a large-area and cost-effective Si platform.