Guided optical modes in asymmetric waveguide cladding with single-negative metamaterials

Abstract

The guided optical modes in the asymmetric slab waveguide with a core of the normal dielectric surrounded by two single-negative (SNG) materials are investigated. The condition for occurring surface waves in the SNG material is analyzed. It is found that the epsilon-negative (ENG) waveguide supports both oscillating and surface guided modes, which is a new feature that the conventional waveguide does not possess. The oscillating guided modes of TM polariton are absent of fundamental mode, while the TE polariton can support the fundamental mode. For higher frequency, larger slab thickness and constitutive parameters, the ENG waveguide accommodates more oscillating guided modes. Furthermore, it is found that the ENG waveguide only supports TM surface guided modes, while the mu-negative (MNG) waveguide only supports TE surface guided modes. The existence of various stable solutions to the surface guided modes depends on the combination of the different constitutive parameters and the structures of waveguide. Finally, the transverse profiles of the surface guided modes in three different regions are obtained.