Surface plasmon propagation in a metal strip waveguide with biaxial substrate

Surface plasmon propagation in a nano metal strip waveguide with a biaxial substrate material was studied. The dispersion of the four fundamental modes propagating in the strip waveguide structure was analysed using a formalism based on the method of lines. The propagation properties of these modes with respect to the thickness of the metal film was studied, with two different biaxial materials as substrate for the waveguide. The results were then compared with the asymmetric strip waveguide structures with isotropic substrate and a uniaxial anisotropic substrate. Propagation characteristics as a function of longitudinal and transverse anisotropic components of the substrate material were also studied. The characteristics of the fundamental modes are observed to vary depending on the anisotropy of the biaxial material used.