A Novel Connection-Based Multicasting Router for Programmable Photonic Circuits

In the rapidly evolving domain of Photonic Integrated Circuits, reconfigurability is making strides through tunable waveguide elements, facilitating ‘general-purpose’ programmable waveguide grids. Routing in modern programmable photonic networks is challenging due to the numerous possibilities that exist for assigning photonic circuits in the grid. Especially the necessary scaling to devices with many more photonic elements calls for more advanced routing heuristics. We can leverage on the existing routers for electronic reconfigurable systems (FPGAs), such as the PathFinder. However, it is crucial to connect network elements while adhering to optical signals' physical restrictions. This complexity requires careful planning for smooth, error-free connections in the network infrastructure. This paper proposes a novel algorithm addressing routing challenges in programmable photonic circuits, specifically multicasting (single-source-multiple-sink) scenarios. Efficiently conserving the overall utilized routing resources stands as a crucial objective in programmable photonics routing. Our algorithm adeptly tackles multicasting routing problems with a particular focus on shortest pathlength multicasting routing. In contrast to the PathFinder, our algorithm demonstrates notable performance in optimization speed and the utilization of routing resources.