NEO-PGA: Nonvolatile electro-optically programmable gate array

Programmable photonic integrated circuits promise reconfigurable, multifunctional photonic systems, analogous to electronic field programmable gate arrays. However, their scalability is constrained by reliance on volatile thermo-optic tuning, which incurs high power consumption, large footprints, and thermal cross-talk. Chalcogenide phase-change materials (PCMs) offer a superior alternative because of their nonvolatility and substantial optical contrast, yet challenges such as optical loss and bit precision have severely hindered their large-scale adoption. Here, we demonstrate low-loss, multibit control of the PCM Sb₂Se₃ using a closed-loop "program-and-verify" approach. We integrate electrically reconfigurable PCM gates into 300-millimeter silicon photonic platforms, implementing both circulating and forward Mach-Zehnder interferometer meshes. The circulating mesh enables broadband switching fabrics and high-Q coupled resonators with unprecedented local control of coupling rates, while the forward mesh supports spatial mode sorting. These results establish a scalable, nonvolatile photonic programmable gate array enabled by PCMs, opening pathways to general-purpose, on-chip programmable photonic systems.