Subwavelength Imaging in a One-Dimensional Metal-Dielectric Structure

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.