A graph-based global routing method for single photonic integrated circuit waveguide connection

作者：Xiaojuan Yang, Guowei Cao, Jiyao Yu, Yu Li · 发表于：Applied Optics and Photonics China · 年份：2023 · DOI：10.1117/12.3007419 · 被引用次数：2 · 研究领域：Engineering

With the integration and design complexity of silicon photonics chips raises, the cost of manual routing based on design experience has significantly increased, which brings urgent demand for auto routing methods. This article proposed a global auto routing method for single waveguide connection in photonic integrated circuits. The method firstly partitions all routable areas into non-uniform grids based on the layout placement information and converts the grids into an undirected graph with respect to the path length and congestion of waveguides between adjacent grids. Next, an improved A* algorithm runs in the graph to find a best path between two optical ports, with additional penalties on every bend in the path, beyond cumulative lengths and congestion penalties. Heuristic terms have also been added to increase the convergence speed of the algorithm. The optimized path in graph is further used to perform multiple adhesive lines for waveguide control points generation. Then, three types of 90-degree bends and two types of S-bend according to specific spacing and angle relationships between control points are applied to generate waveguide trace. This method can avoid collisions between target waveguide and other devices on the layout, optimize the global path length, minimize the number of waveguide’s bends, prevent waveguide congestion in specific spaces from exceeding the set threshold, and at the same time generate the optimal waveguide and insert it into layout.