Enhancement of evanescent waves in waveguides using uniaxially anisotropic metamaterials with an arbitrary angle between the optical axis and the interface

Abstract

ABSTRACTF The enhancement of evanescent waves in multilayer planar waveguides with a uniaxially anisotropic metamaterials layer is investigated. Without loss of generality, we assume that the anisotropic metamaterials ha ve an arbitrar y angle between the optical axis and the interface, and then we derive the char acteristic equations and the anal ytical expression of energy flux of this waveguides. It is found that the enhancement f actor increases rapidly at first with increasing of the thickness of the metamaterials in the case when the optical axis is parallel to or normal to the interface, namely the angle is equal to 0 or Œ/2. The enhancement factor eventually reaches its maximum when complete surface polaritons are established at the boundary between the metamaterials an d the cladding [D.-K. Qing, G. Chen, Appl. Phy. Lett. 84(5), 669-671 (2004).]. Numerical results confirm our theoretical analysis. Keywords : enhancement of evanescent wave s, metamaterials, uniaxially anisotropic, planar waveguide