On simulating light diffraction by layered structures with multiple wedges

Layered structures containing small-angle wedges are widely used as linear variable filters (LVFs) in microspectrometers, sensors, and hyperspectral imaging systems. Here, we propose a method based on the scattering matrix formalism allowing one to describe the optical properties of layered structures with multiple wedges. As examples, we consider a single-wedge LVF with Bragg claddings and an LVF with three wedges, the latter exhibiting a flat-top resonant transmission peak. We show that the proposed method provides a two orders of magnitude increase in speed compared to the rigorous numerical simulations based on the Fourier modal method. At the same time, as we demonstrate, the results obtained with these two methods are very close to each other. The proposed approach is promising for the design and investigation of LVFs containing several wedge-shaped layers.