Unconventional Monolithic Electronics in a Conventional Silicon Photonics Platform

To enrich state-of-the-art optical chips with electronic functionalities, we present the integration of unconventional transistors and circuits in a standard silicon photonics platform, with no modifications to the conventional fabrication process employed by photonic foundries. This approach allows us to include on-chip electronic building blocks to support the optical functionality at zero additional cost while maintaining optical excellence and foundry interoperability. To showcase the benefits of monolithic electronics, we integrated a transconductance amplifier and an analog multiplexer for sequential readout of 16 photodetectors, distributed in a large-scale architecture of Mach–Zehnder interferometers (MZIs). The circuits, successfully validated in optical experiments, allow the reduction of electrical input-output lines of a photonic chip without any optical penalty, thus targeting one of the main bottlenecks that limit further scaling of photonic circuits.