Kaiyin Feng

Presents corrections to the author listings in the paper, “Quantum Dot DBR Lasers Monolithically Integrated on Silicon Photonics by In-Pocket Heteroepitaxy,” (Koscica, R., et al., 2025).

The direct growth of III-V lasers on silicon has the potential to allow for low-cost production of silicon photonic integrated circuits on a 300 mm wafer-scale. However, coupling loss severely limits the performance in current implementations of direct growth processes due to the growth of undesirable polycrystalline material on silicon dioxide sidewalls. In this work, we report the use of selective area molecular beam epitaxy growth to reduce the formation of this polycrystalline material during the growth process and improve the coupling efficiency. Furthermore, we demonstrate electrically pumped continuous wave lasers directly grown on foundry-fabricated silicon photonic integrated circuit wafers using this technique.

Monolithically integrated lasers on silicon photonics enable scalable, foundry-compatible production for data communications applications. However, material mismatches in heteroepitaxial systems and high coupling losses pose challenges for III-V integration on silicon. We combine three techniques: recessed silicon pockets for III-V growth, two-step heteroepitaxy using both MOCVD and MBE, and a polymer facet gap-fill approach to develop O-band InAs quantum dot lasers monolithically integrated on silicon photonics chiplets. Lasers coupled to silicon ring resonators and silicon nitride distributed Bragg reflectors (DBR) demonstrate single-mode lasing with side-mode suppression ratio up to 32 dB. Devices lase at temperatures up to 105 °C with an extrapolated operational lifetime of 6.2 years at 35 °C.

Low-confinement silicon nitride (SiN) waveguides offer ultra-low losses but require wide bend radii to avoid radiative losses. To realize the benefits of silicon nitride in a heterogeneous laser while maintaining a small footprint, we employ metal-coated etched facets and transversely coupled Fabry–Perot resonators as mirrors. Heterogeneous quantum dot lasers are fabricated using an on-chip facet plus adiabatic taper coupler, and Fabry–Perot cavities are defined by metal mirrors and post-grating-distributed Bragg reflectors (DBRs). Threshold current densities below 250 A/cm² are observed, and a power >15 mW is measured in an integrating sphere. A laser linewidth of 2.

2023 International Conference on Solid State Devices and Materials ,Quantum Dot Lasers on Silicon for Monolithic Photonic Integrated Circuits

We report for the first time the direct growth of quantum dot (QD) lasers with electrical pumping on 300 mm Si wafers on both a planar template and in-pocket template for in-plane photonic integration. O-band lasers with five QD layers were grown with molecular beam epitaxy (MBE) in a 300 mm reactor and then fabricated into standard Fabry–Perot ridge waveguide cavities. Edge-emitting lasers are demonstrated with high yield and reliable results ready for commercialization and scaled production, and efforts to make monolithically integrated lasing cavities grown on silicon-on-insulator (SOI) wafers vertically aligned and coupled to SiN waveguides on the same chip show the potential for 300 mm-scale Si photonic integration with in-pocket direct MBE growth.

We discuss the physical processes for the degradation of quantum-dot lasers epitaxially grown on silicon. Through combined electro-optical measurements and deep-level transient spectroscopy, we conclude a pathway to obtain significant improvement in device lifetime.

Monolithic integration of quantum dot (QD) gain materials onto Si photonic platforms via direct epitaxial growth is a promising solution for on-chip light sources. Recent developments have demonstrated superior device reliability in blanket hetero-epitaxy of III–V devices on Si at elevated temperatures. Yet, thick, defect management epi designs prevent vertical light coupling from the gain region to the Si-on-Insulator waveguides. Here, we demonstrate the first electrically pumped QD lasers grown by molecular beam epitaxy on a 300 mm patterned (001) Si wafer with a butt-coupled configuration. Unique growth and fabrication challenges imposed by the template architecture have been resolved, contributing to continuous wave lasing to 60 °C and a maximum double-side output power of 126.6 mW at 20 °C with a double-side wall-plug efficiency of 8.6%. The potential for robust on-chip laser operation and efficient low-loss light coupling to Si photonic circuits makes this heteroepitaxial integration platform on Si promising for scalable and low-cost mass production.

Monolithic integration of quantum dot (QD) gain materials onto Si photonic platforms via direct epitaxial growth is a promising solution for on-chip light sources. Recent developments have demonstrated superior device reliability in blanket hetero-epitaxy of III-V devices on Si at elevated temperatures. Yet, thick, defect management epi designs prevent vertical light coupling from the gain region to the Si-on-Insulator (SOI) waveguides. Here, we demonstrate the first electrically pumped QD lasers grown on a 300 mm patterned (001) Si wafer with a butt-coupled configuration by molecular beam epitaxy (MBE). Unique growth and fabrication challenges imposed by the template architecture have been resolved, contributing to continuous wave lasing to 60 {\deg}C and a maximum double-side output power of 126.6 mW at 20 {\deg}C with a double-side wall plug efficiency of 8.6%. The potential for robust on-chip laser operation and efficient low-loss light coupling to Si photonic circuits makes this heteroepitaxial integration platform on Si promising for scalable and low-cost mass production.