Metal Composite Surface Of The Goos - Hänchen Effect

Goos-Hanchen Effect (GHE) is a phenomenon that when a light beam incident on the interface between two different media, there will be a displacement of the reflected beam if compared to the geometric reflection. F. Goos and H. Hanchen first found this effect in an ingenious experiment, so it is named in the two scientists'last name. Since it was discovered, GHE have received much attention in physics world for its profound physical meaning and potential applications. Especially with the recent exploration of various kinds of artificial functional materials, GHE has attracted much interest.In this paper, we study the GHE on the surface of metal composites. The thesis is organized as follows:Ⅰ. Temperature-dependent Goos-Hanchen shift on the interface of metal/dielectric nanogranular compositesWith the stationary-phase method, we study the Goos-Hanchen shift (GHS) of the reflected electromagnetic wave on the surface of metal/dielectric nanogranular composites. We choose the Drude model to describe the dielectric function of the metal component, and introduce the temperature dependence of the plasma and collision frequencies of the metal. Then we make use of Bruggeman effective medium theory (EMT) to derive the temperature-dependent effective permittivityεe(T) of the metal-dielectric composites. In the end, we study the Goos-Hanchen shift as a function of the incident angle and temperature. The result shows that, for dielectric composites, the effect of the temperature on GHS is significant near the Brewster angle; but for the metal composites, this happens at the grazing angle. Moreover, the lateral shift can be negative as well as positive for dielectric composites. And GHS may become more negative, more positive, and nonmonotonic variation with increasing the temperature under different conditions. In addition, through the suitable adjustment of the temperature, we may realize the reversal of the sign of the GHS. We take one step forward to provide numerical simulations for Gaussian incident beams based on the momentum method and COMSOL Multiphysics software, and one can find reasonable agreement between the theoretical results and numerical simulations when the width of the Gaussian beams is sufficiently large.Ⅱ. Goos-Hanchen Effect on the surface of uniaxially anisotropic metal/dielectric compositesWe study the GHS of the reflected light on the surface of uniaxially anisotropic metal/dielectric composites. We find that the lateral shift can be negative or positive for different volume fractions of metal particles. However, when the absorption is strong, the GHS on the surface of the composites is always negative independent of the positive or negative refraction. When the absorption is weak, the lateral shift for the composites with positive refraction will exhibit a positive displacement. On the other hand, the GHS of the negative refractive material can be positive as well as negative. That is, when the negative refraction of the composites is weak the lateral shift is still positive; while the GHS will be negative when the negative refraction becomes strong enough. To confirm the validity of our conclusions, we use both Gaussian beams and COMSOL Multiphysics software to simulate our theoretical results.