Adjoint-Based Sensitivity Analysis for Silicon Photonic Variations

With the rising demand for integrated silicon photonics as a technology platform, it becomes crucial to provide variation-aware models and design for manufacturability (DFM) methods to inform the design of silicon photonic devices and circuits. In this paper, we demonstrate the application of the adjoint method to estimating the sensitivity of photonic components against key process variations inherited from integrated circuit fabrication technologies. In particular, we examine the impact of line edge roughness (LER) on a passive Y-branch, and validate our results with ensemble virtual fabrication simulations. The adjoint sensitivity and variance estimation of Y-branch transmission imbalance is seen to be highly efficient in comparison to direct ensemble simulation.