Multiphysics Design and Simulation Methodology for Dense WDM Silicon Photonics

Abstract

We present a novel design methodology covering multiphysics simulation workflows for microring-based dense wavelength division multiplexing (DWDM) Silicon Photonics (SiPh) circuits used for high-performance computing systems and data centers. The main workflow is an electronics-photonics co-simulation comprising various optical devices from a SiPh process design kit (PDK), electronic circuits designed with a commercial CMOS foundry's PDK, and channel S-parameter models, such as interposers and packages, generated by using a full-wave electromagnetic (EM) solver. With the co-simulation, electrical and optical as well as electro-optical behaviors can be analyzed at the same time because best-in-class electronics and photonic integrated circuit simulators interact with each other. As a result, not only optical spectrum and eye diagrams but also electrical eye diagrams can be evaluated on the same simulation platform. In addition, the proposed methodology includes a statistical- and thermal-aware photonic circuit simulation workflow to evaluate process and temperature variations as well as estimate the required thermal tuning power as those non-idealities can lead to microring's resonance wavelengths shifting. For this, thermal simulation is conducted with a 3D EM model which is also used for such signal and power integrity analysis as a channel link simulation and IR drop. Also, photonic circuit simulations are performed where a design exploration and optimization of such microring's design parameters as Q-factor, and bias voltages are required to select the most promising designs, for example, to satisfy a specific bit-error rate. With the proposed design methodology having those multiphysics simulation workflows, DWDM SiPh can be fully optimized to have reliable system performance.