Efficient sensitivity analysis of waveguide structures using Finite Element Method (FEM)

We discuss a novel finite element method-based technique for estimating accurate sensitivities of the desired response. Our technique utilizes the central adjoint variable method (CAVM) for estimating the response sensitivities. This approach features accuracy comparable to that of the central finite difference (CFD) approximation at the response level. Our approach uses a simple perturbation method to calculate the sensitivity of modal parameters of various waveguide structures with respect to the geometric and material parameters. No additional simulation is required to calculate the response and its sensitivity with respect to all the design parameters. The accuracy of our approach is illustrated by comparing the results with the second order accurate CFD applied on the response level. Our results show a very good agreement between the CAVM-based sensitivities and those obtained using the expensive central.