Optimizing bend loss in optical waveguide channel routing on photonic integrated circuits

Abstract

Silicon photonics (Si-photonics) has been established as a potential technology that integrates both electronic and optical circuits on single integrated circuits (ICs) in order to satisfy the increasing demand for high-speed and low-power in the emerging market of ICs. It has opened up the research directions in the domain of design automation for photonic ICs. On the physical layout of the optical circuits, it is a challenging task to obtain the optimal routing of optical waveguides, while minimizing all the parameters like the number of tracks, total bend loss, worst signal loss, total propagation loss and total crossing loss. In this paper, we proposed two non-Manhattan grid-based methods for reducing the bend loss, worst signal loss and tracks in optical channel routing. First, a 0-1 integer linear programming (ILP) based algorithm called minimizing bend loss (MBL) is proposed, which minimizes the total bend loss (TBL) and the worst signal loss (WSL) while reducing the number of tracks (T ) over the state-of-the-art technique. The execution time of MBL is very high for the large input. Hence next, a scalable heuristic called reducing bend loss (RBL) is presented that provides a better balance between the reduction of the TBL and T over the state-of-the-art and MBL algorithms. Simulation results show that MBL can reduce the TBL and the WSL by an average of 57.9% and 63.1%, respectively, with an average increase of 12% in T over state-of-the-art algorithms. The simulation results show that the RBL reduces the TBL and the WSL by an average of 39.7% and 41.3%, respectively, with an average increase of 23.7% in T over state-of-the-art algorithms.