Guided-Mode Resonance Filter Compensated to Operate on a Curved Surface
Guided-mode resonance filters (GMRFs) are highly compact structures that can produce a strong frequency response from a single thin layer of dielectric. When a GMRF is formed onto a curved surface, the local angle of incidence varies over the aperture of the device and the overall performance significantly degrades. In the present work, we spatially varied the grating period of a curved GMRF to perfectly compensate for the local angle of incidence. The performance of the curved device actually surpassed that of a flat device because it also compensated for the spherical wave front from the source. This paper summarizes our design process and experimental results obtained around 25 GHz.