Rosalyn Koscica

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.

O-band quantum dot lasers are monolithically integrated on silicon photonics using MOCVD/MBE growth and a facet fill approach to reduce waveguide coupling loss below 6 dB. Lasers achieve ring resonator coupling and single-mode lasing.

Ultralow-noise laser sources are crucial for a variety of applications, including microwave synthesizers, optical gyroscopes and the manipulation of quantum systems. Silicon photonics has emerged as a promising solution for high-coherence applications due to its ability to reduce the system size, weight, power consumption and cost. Semiconductor lasers based on self-injection locking have achieved fibre laser coherence, but typically require a high-quality-factor external cavity to suppress coherence collapse through frequency-selective feedback. Lasers based on external-cavity locking are a low-cost and turnkey operation option, but their coherence is generally inferior to self-injection locking lasers. In this work, we demonstrate quantum-dot lasers grown directly on Si that achieve self-injection-locking laser coherence under turnkey external-cavity locking. The high-performance quantum-dot laser offers a scalable and low-cost heteroepitaxial integration platform. Moreover, the chaos-free nature of the quantum-dot laser enables a 16 Hz Lorentzian linewidth under external-cavity locking using a low-quality-factor external cavity, and improves the frequency noise by an additional order of magnitude compared with conventional quantum-well lasers.

Epitaxially grown quantum dot (QD) lasers in narrow pockets on patterned silicon photonics wafers present a key step toward full monolithic integration of on‐chip light sources. However, InAs QD lasers grown in deep and narrow pockets demonstrate limited performance and reliability compared to planar‐grown counterparts. Herein, InAs QD lasers are grown in patterned SiO₂ pockets atop planar thermal cyclic annealed GaAs on (001) Si substrate with reduced threading dislocation density, enabling detailed study of how pocket geometry impacts device performance. Fabry–Pérot lasers with cleaved facets exhibit strong variation in performance based on the dimensions of the pocket, wherein thermal and optical metrics improve with increasing pocket width. Devices lase up to a maximum stage temperature of 115 °C with an extrapolated lifetime of 2.2 years at 80 °C for material grown in 50 μm by 3900 μm pockets. This study addresses, the ongoing challenge of optimizing pocket‐grown devices to planar equivalent performance.

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.