The Negative Refraction And Subwavelength Imaging Study On Layered Metal-Dielectric Structure

Recently, negative refraction materials have received much attention by the academic world due to their unique properties and alluring applications, which is becoming one of the front and hot focuses both for electromagnetic and optical research .Because of its potential applications in near field optics, especially in superlens phenomena and sub-diffraction-limit imaging, more and more scientists devote to the research on physical properties, experimental fabrication and numerical simulations of negative refraction media from microwave frequencies to visible lights.In this dissertation, effective media dispersion theoretical analysis is used to analyze the negative refraction effect of layered metal-dielectric structure. FDTD numerical simulation is used to study the superlens phenomena in the layered metal-dielectric structure. The main work is divided into four parts: dispersion of layered metal-dielectric structure, negative refraction on the interface, superlens phenomena and hyperlens.The main research works and conclusions are as following:1. From effective media theory, dispersion relation of layered metal-dielectric structure is obtained to demonstrate the all-angle negative refraction of metal waveguide arrays (MWGAs), analyzed the beam refraction on different gradient interface. The rule for decide the direction the energy direction in the k space is provided and possible combinations for refraction of wave vector and energy flux are given. Investigating the eige electromagnetic modes in anisotropic media in cylindrical coordinates, and the physics of far-field magnification hyperlens is studied by using effective media dispersion theoretical analysis. This analysis of k space dispersion curve provides clear and simple physics image and have advantage in constructing layered structure.2. Combining Drude dispersion model, two-dimensional double dispersive FDTD simulation software is developed which can accurately simulate the optical phenomena related to dielectric, metal and negative index media. FDTD numerical simulation is used to study the superlens phenomena in the layered metal-dielectric structure. By constructing output interface topography, sharper superdiffraction limit imaging is obtained, resolving power is improved to 179%, which has great applications in near-field photolithography and sub-diffraction-limit imaging.3. FDTD numerical simulation is used to study the superlens phenomena in the hyperlens. Influence of curvature radius and layer number of hyperlens on the beam propagation and divergence is studied which is beneficial to the construction of hyperlens. Wavelength range of incident light is also studied to obtain the operating bandwidth of hyperlens. Inventing a curving sub-diffraction-limit carrier pipe which can be used on nanoscale biologic and metallic structure far-field imaging by using hyperlens. 0.3λand 0.44λresolving is obtained and it has great applications in biologic molecule and metallic nanoscale structure detecting.Highlights of the dissertation are as following:1. From effective media theory, dispersion relation of layered metal-dielectric structure is obtained to analyze the all-angle negative refraction and beam refraction on gradient interface of metal waveguide arrays, and the physics of far-field magnification hyperlens.2. FDTD numerical simulation is used to study the superlens phenomena in the layered metal-dielectric structure. By constructing output interface topography, sharper superdiffraction limit imaging is obtained.3. Influence of curvature radius and layer number of hyperlens and wide spectrum on the beam propagation and divergence is studied. Inventing a curving far-field sub-diffraction-limit carrier pipe.