Hybrid Integration of InGaN Lasers in a Foundry-Fabricated Visible-Light Photonics Platform

Visible-spectrum photonic integrated circuits (PICs) present compact, scalable solutions for quantum computing, biosensing, and virtual/augmented reality. Realizing their potential requires scalable visible-light-source integration methods compatible with high-volume manufacturing and efficient optical coupling. Here, we demonstrate passive-alignment flip-chip bonding of 450-nm InGaN laser diodes onto a foundry-fabricated visible-light silicon (Si) photonics platform with silicon nitride (SiN) waveguides, thermo-optic devices, and photodetectors. Hybrid laser integration is realized using a sub-micron-precision die bonder with a vision alignment system and heatable pickup tool, allowing placement of multiple lasers on a single Si chip. Co-design of the lasers and Si photonics, with lithographically defined alignment marks and mechanical stoppers, enables precise post-bonding alignment. Efficient coupling to SiN waveguides is demonstrated, with a 1.1 dB minimum coupling loss. We measure 19.0 mW mean on-chip optical power at 90 mA drive current; at 185 mA, maximum on-chip power reaches 60.7 mW, the highest reported for hybrid-integrated visible-spectrum lasers, to our knowledge. A maximum wall-plug efficiency of 7.8% is measured. An active PIC is shown, integrating a bonded laser, photodetector power monitor, and thermo-optic switch for routing and variable attenuation. This work highlights passive-alignment flip-chip bonding as a practical, high-performance approach for integrating lasers onto visible-spectrum PICs.