Double-channeled omnidirectional filtering properties of the sandwich structures composed of single-negative materials

¹ School of Physics and Chemistry, Henan Polytechnic University, Jiaozuo 454000, P.R. China
² Pohl Institute of Solid State Physics, Tongji University, Shanghai 200092, P.R. China
³ School of Space Science and Physics, Shandong University at Weihai, Weihai 264209, P.R. China

Corresponding author: zlwted@hotmail.com

Received: 25 October 2008
Revised: 4 February 2009
Accepted: 5 March 2009
Published online: 22 April 2009

Abstract

Double-channeled omnidirectional filtering properties are found in the sandwich structure composed of a ε-negative layer and a μ-negative layer separated by another single-negative layer with either dielectric permittivity or magnetic permeability described by Lorentz model. The twin tunneling interface modes are generated by the excitation of surface polaritons. It is shown that the two tunneling modes are insensitive to the incidence angles and the polarizations. Furthermore, the tunneling frequency and the frequency interval of the two modes can be tuned by changing the resonance frequency and the thickness of the center layer respectively. The characteristics can be utilized to design double-channeled tunable omnidirectional filters using in microwave and optical engineering.