Spatial filtering of evanescent waves with rough multilayer hyperbolic metamaterials

Abstract

Hyperbolic metamaterials acting as spatial filters, passing incident evanescent waves and blocking incident propagating waves, can be produced for ultraviolet wavelengths by a stack of alternating metal/dielectric films. However, real fabricated devices have disordered layer surfaces due to imperfect material deposition. Here, we investigate the effect of realistic surface roughness on the spatial filtering properties of such devices. The findings have implications in subdiffraction imaging and photolithography.