Opto-Electronic Simulation of Silicon Waveguide Integrated Single Photon Avalanche Diodes

Single-photon avalanche diodes (SPADs) integrated into photonic integrated circuits (PICs) can offer a promising alternative to cryogenic superconducting detectors, combining CMOS compatibility with room-temperature operation. However, this remains an underexplored area of study despite the potential. A comprehensive optoelectronic multiphysics simulation framework to model waveguide integrated SPADs is shown here. A device based on imec's isipp50g technology is simulated and shown to have peak photon detection efficiencies (PDE) above 75% at 600 nm,when coupled with a SiN signal waveguide. This work establishes a scalable methodology for design technology co-optimization (DTCO) of SPADs for integrated photonics, and identifies critical pathways towards performance improvements, paving the way for their full optimization and integration into quantum photonic circuits.