Research On Negative Index Media By Using Theoretical And Numerical Methods

Negative index meddia used to be a hypothetical concept developed by scientists, while recent theoretical and experimental results have confirmed that such media can be fabricated and analyzed. Because of its potential applications in near field optics, more and more people devote to the research on physical properties, experimental fabrication and numerical simulations of such media.In this dissertation, by using theoretical analysis and numerical simulation, we explore the physical properties and potential applications of negative index media. The main work are divided into four parts: double-dispersive finite-difference time-domain (FDTD) method that is applicable to negative index media, properties of superlens, anisotropic media and surface waves.The main research works and conclusions are as following:1. Combining Drude dispersion model, one, two and three-dimensional double dispersive FDTD simulation software is developed independently by us, which can accurately simulate the optical phenomena related to dielectric, metal and negative index media. Using the developed software, we study the propagation and scattering properties of both short pulse and wave packet in negative index media, and suppression and broadening effects as well as the conservation of energy are observed. We also demonstrate the negative refraction, the imaging ability for a planar slab of negative index media and other phenomena.2. Proposing a general transfer matrix method that take the same form for both propagating wave and evanescent wave. Using this method, we demonstrate the focusing ability of perfect lens and investigate the influence of absorption, period, and the thickness of the resolution of compound superlens. The results show that applying compound superlens does reduce the influence of absorption and increase the thickness of the slab while achieving the same resolution.3. Investigating the eigen electromagnetic modes in anisotropic media, and possible degeneration of modes is found. The rule for decide the direction the energy direction in the k space is provided. The refraction at the interface between an isotropic dielectric and an an isotropic media is studied thoroughly, and all...