An Analytical Method for Evaluating the Robustness of Photonic Integrated Circuits

We propose an efficient analytical method to evaluate the robustness of integrated photonic devices and circuits in the presence of independently-distributed random variations in the device parameters. By approximating the output of a photonic system in terms of a first or second-order Taylor series, we derive closed-form expressions for the mean and variance of the system output, which allow us to compute the one-standard-deviation (1-sigma) bounds on the expected system performance. Compared to other approaches for evaluating robustness, our method does not require computationally-intensive numerical simulations of the system output and can apply to any statistical distribution of parameter variations, including uniform and normal distributions. We demonstrate the method by analyzing the robustness of two coupled resonator systems: a fifth-order microring filter, and optical delay lines based on 1D Coupled Resonator Optical Waveguides and 2D Floquet topological microring lattice. Our method could provide a useful tool in the design and analysis of robust optical devices and circuits.