Design a Stratiform Metamaterial with Precise Optical Property

Abstract

In this work, a stratiform metamaterial is arranged as multiple periods of metal-dielectric symmetrical film stack to provide precise equivalent refractive index and admittance. There are multiple solutions of equivalent refractive index retrieved from the characteristic matrix of the film stack. The correct refractive index is derived by connecting different branches of solution at different ranges of wavelength or thickness of the dielectric layer. The refractive index of an Ag-TiO 2 five-layered symmetrical film stack shown in previous work is demonstrated to be positive real instead of negative real. The associated type I iso-frequency curve supports negative refraction. In order to extend the operating wavelength of type I metamaterial, the number of the metal-dielectric symmetrical film stack is increased to reduce the thickness of the dielectric film to approach subwavelength requirement.

Design of a Hyperbolic Metamaterial as a Waveguide for Low-Loss Propagation of Plasmonic Wave

“…), respectively, where θ is the angle of incidence, λ is wavelength of incident wave, and P i are optical constants of each composite thin film including refractive index and thickness. To obtain N eq , one of the multiple branches of the equivalent refractive index must be selected by imposing the requirement of continuity: the equivalent refractive index and the equivalent admittance of any film versus wavelength or thickness must be continuous [30]. According to the definition of the phasor of field e ιωt , the real part of the equivalent admittance has to be positive and the imaginary part of the equivalent refractive index must be negative [31,32].…”