Modal analysis of metallic screen with finite conductivity perforated by array of subwavelength rectangular flared holes

An array of flared rectangular holes pierced through a conducting screen is treated herein by a rigorous full-wave modal analysis using the moment method entailing Green's functions for rectangular cavities and planar multilayer structures in the spectral domain as well as classical Floquet theorem and the mode-matching technique. In this way, flared holes with arbitrary taper profile that may each even be composed of different dielectric sections and which perforated metal films that may be sandwiched between multiple layers of dielectric slabs on both sides is herein treated. The eclectic permutations of geometrical, structural, and material attributes thus afforded by this generic topology facilitate correspondingly diverse investigations that may prove pivotal to the success of future explorations in search for new breakthrough discoveries and innovations in the subject of extraordinary transmission through subwavelength hole arrays, to which the herein-analyzed configuration is central. Oblique angles of incidence for both principal polarizations and metal losses incurred by imperfect conducting screens are also investigated in this work, all constituting crucial aspects that may often be neglected.