Low-defect InAs/InGaAs quantum dot lasers directly grown on silicon: scalable fabrication and high-temperature laser characterization

Direct epitaxial growth of III–V quantum-dot (QD) gain media on silicon offers a route to wafer-scale, monolithically integrated light sources with minimal assembly overhead, but is typically limited by mismatch-induced defects and associated thermal sensitivity. Building on our recently developed low-defect III–V-on-Si platform, here we focus on scalable device processing and characterization of Fabry–Perot lasers emitting at 1.3 μm. We summarize the epitaxial design, fabrication flow, and representative temperature-dependent laser characteristics for both broad-area and narrow ridge geometries. Broad-area devices exhibit a low continuous-wave (CW) threshold current density of 54 A cm⁻² at room temperature and maintain lasing up to 125 °C. Narrow ridge-waveguide lasers achieve low CW thresholds, down to 6 mA at room temperature and 12 mA at 80 °C. Additionally, they sustain operation up to 165 °C, while maintaining high output power at elevated temperatures, including tens of mW at 80 °C for optimized facet conditions. Moreover, comparison with nominally identical devices processed in parallel on GaAs indicates essentially equivalent threshold performance, supporting the conclusion that mismatch-related limitations can be strongly mitigated through optimized epitaxy and fabrication. These results outline a practical route toward high-temperature-tolerant laser sources monolithically integrated on silicon for photonic applications.