On the constitutive relations of G-chiral media and the possibility to realize negative-index media

Abstract

Gyro-chiral (G-chiral) media of different constitutive relations are studied as potential materials to realize the negative-index material (NIM). G-chiral media are believed to have advantages over chiral media: negative refractive index and backward waves can be achieved without requiring the permittivity and permeability to be quite small at working frequency. The gyrotropic parameters favor the realization of NIM far off the resonances of the permittivity and permeability. The possibility of obtaining backward waves and negative refractive index under Post's and Tellegen's relations are discussed. Moreover, the mapping and comparison of G-chiral media of these two relations have been studied. It is found that the Tellegen's relations are more suitable to describing the G-chiral media so as to realize NIM by this kind of medium. Therefore, this paper not only provides an alternative way to achieve NIM from the G-chiral medium but also discusses the constitutive relation's effects on backward wave propagation and refractive indices. © 2006 Wiley Periodicals, Inc.