Infrared Colloidal Quantum Dot Edge Emitting Lasers Integrated on Silicon

ABSTRACT The monolithical integration of infrared (IR) laser sources onto a silicon platform remains a fundamental challenge in advancing silicon photonics, largely due to the lattice mismatch between silicon and conventional epitaxial semiconductors. In this work, we report the first demonstration of edge‐emitting, first‐order distributed feedback (DFB) lasers based on solution‐processed colloidal quantum dots (CQDs) integrated onto a silicon/silicon dioxide (Si/SiO ₂ ) platform. By systematically optimizing the buried oxide (BOX) layer thickness, we identify a 5 µm threshold required to suppress mode leakage into the high‐index silicon substrate and maximize modal gain. By carefully optimizing the grating duty cycle and incorporating a λ/4 phase shift, we achieved spectrally pure, single‐mode lasing with a narrow linewidth of 0.9 meV (2.1 nm), tunable across the 1580 –1680 nm range on a silicon platform. This work establishes a scalable, CMOS‐compatible strategy for on‐chip infrared lasers, overcoming a critical bottleneck for fully integrated silicon photonics.