1.5 μm quantum-dot diode lasers directly grown on CMOS-standard (001) silicon

Abstract

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.

Degradation of III–V Quantum Dot Lasers Grown Directly on Silicon Substrates

“…Incorporating multiple defect filter layers, combined with in-situ thermal annealing during growth, has shown to dramatically reduce the threshold current of III-V lasers on Si and, with relevance for the work presented later, to cause an increase in the lasing wavelength [7]. Devices have recently been demonstrated with performance which is competitive to those grown on native substrates [2], [8]- [10] and extended to InAs dots on InP on Si and lasers emitting in the 1.55 µm wavelength range [11].…”

O-Band and C/L-Band III-V Quantum Dot Lasers Monolithically Grown on Ge and Si Substrate

“…In addition, as previously stated, most of the work so far has referred to the 1.3 µm wavelength at the O-band telecom window. Few work regarding the emission at the C/L-band telecom window has been reported to date [50,64]. Long wavelength III-V light sources on Si substrates at 1550 nm or C/L-band have become strongly demanded, since most of the Si-based photonic passive and active devices are based on applications at the C-band window.…”

“…The novel epitaxy approach to integrate GaAs on silicon relies on aspect ratio trapping (ART) of defects in narrow oxide trenches to suppress the threading dislocations. The misfit strain by the formation of twinned stacking faults (SFs) is relaxed through using the V-groove structure [49][50][51]60,64,71,72]. This method stands out for its capability in defect trapping, good controllability and high compatibility with the Si CMOS process.…”

“…Although APDs are avoided by the grooves and most dislocations are confined to the interface, there is still no way to release the thermal mismatch. In addition, 1550 nm quantum dot diode lasers have been realized on CMOS-standard (001) silicon substrate, but with a very thick GaAs intermediate buffer layer of 2.2 µm [64]. Therefore, a novel method is strongly demanded to improve the laser structure for the reduction of thermal mismatch, for less TDs and better laser performance.…”

“…Otherwise, patterned (001) silicon substrate or InP was utilized in the heterostructures. For the C-band or L-band telecom window, there are very few works that have been reported [50,64]. Since many of the Si photonic passive and active devices are based on C-band applications, III-V light sources on Si in the long-wavelength range are becoming strongly demanded.…”