Subwavelength imaging of a multilayered superlens with layers of nonequal thickness

We propose a multilayered superlens comprising alternately layered metal and dielectric films with layers of nonequal thickness to realize subwavelength imaging, even when permittivities of the metal and dielectric are mismatched. Based on ideal imaging conditions, the exact constraint relations about the thickness of each dielectric layer and the permittivity of the surrounding medium of the multilayered superlens are first acquired when the superlens is modeled by the effective medium theory. Theoretical analysis and numerical simulations indicate that a multilayered superlens with constraint relations can realize subwavelength imaging at wavelengths of 335 to 385 nm.