Subwavelength Imaging in a One-Dimensional Metal-Dielectric Structure

Abstract

We analyse the dispersion relation of a one-dimensional (1D) metal-dielectric (MD) structure for H-polarized light (i.e. the magnetic field is parallel to the interfaces of the layers) and use the transfer matrix method to simulate the subwavelength image effect through the 1D-MD structure. The structure operates in the self-collimation regime, and does not involve negative refraction or amplification of evanescent waves. The Fabry–Perot resonance effect is studied in order to obtain optimum parameters for maximum transmission. A resolution of λ/10 for a single point source is achieved when the thickness of the 1D-MD is about 300 nm. Taking into account the actual values of the dielectric constants of the metal (silver) and the dielectric (HfO2) layers, we find that a silver/HfO2 stack, with suitable parameters, has a resolution of λ/5 at visible wavelengths.