A Zero-Crossing Optical Waveguide Routing Method

Photonic Network on Wafer (PNoW) for multi-chip computing systems is a promising solution for providing high inter-chip bandwidth while maintaining low energy consumption. This paper introduces a novel approach for routing optical waveguides in PNoWs on a 2-dimensional wafer plane, eliminating the need for any waveguide crossings. Our proposed method guarantees zero optical waveguide crossings, therefore high signal-to-noise ratio (SNR) and low signal loss in the photonics circuits. Notably, our proposed routing method is applicable to PNoWs with significantly higher inter-chip bandwidth, surpassing current commercial products by one magnitude. In contrast, we demonstrate that classical routing heuristics that allow waveguide crossings might result in a substantial degradation in terms of signal qualities, which is evaluated with certain approximations in this work. Furthermore, our grid-less routing method imposes minimal computational requirements, offering an efficient and practical solution for the implementation of high-performance PNoWs.