Automated assembly of hybrid-integrated, chip-scale laser systems

Hybrid photonic integration provides a platform to design and implement novel functionalities unavailable to active or passive material systems alone. We present an automated alignment and assembly process for hybrid-integrated laser systems, comprising silicon nitride (Si₃N₄) photonic integrated circuits (PICs) edge-coupled to gallium arsenide (GaAs) gain chips (GCs). We design and optimize spot size converters (SSCs) to increase the alignment tolerances between the PICs and GCs. Our automated assembly process has achieved experimental coupling losses of 2.7 dB between the PICs and GCs, closely matching the simulated values. Packaged hybrid lasers, when coupled to a lensed fiber, exhibit slope efficiencies of ∼ 97 mW/A. These results show the feasibility of scaling the production and widespread application of these hybrid laser systems by automating their assembly, which should drive down packaging costs and accelerate research.