PROPAGATION OF SURFACE ELECTROMAGNETIC WAVES GUIDED BY PERIODIC AND APERIODIC MEDIUMS

Abstract

In tIlls thesis, the surface electromagnetic wave (SE-wave) propagation guided by a single interface of two dissinlilar periodic dielectric materials and slab waveguides comprised of aperiodic materials were studied theoretically and numerically, in optical as well as microwave regimes. The SE-wave known as Tamm wave was investigated at the planar interface of two dissimilar multilayered periodic homogeneous dielectric slab for varying applied wavelength willIe keeping all other parameters fixed. The numerical results predicted t hat no SE-wave of s and p polarization states exist along the interface of two distinct multilayered periodic homogeneous dielectric materials. TIllS signified t hat the Tamm wave can only be excited at t he interface of two dissimilar materials if the material is nonhomogeneous normal to the plane of interface. For t he investigation of tIllS aspect, the canonical problem of surface-wave propagation guided by the interface of two senli-infinite rugate filters made of isotropic dielectric materials with sinusoidal refractive index profiles was formulated and solved. Numerical studies showed that multiple Tamm waveswith different phase speeds, polarization states, and degrees of localization- can be guided by the interface of a homogeneous dielectric material and a rugate filter. Like surface plasmon polariton (SPP) wave, willch exists at the planar interface of a metal and a dielectric material; it can also be possible to create surface wave- known as Fano wave-- at the planar interface of a positive and a negative relative pernlittivity materials. For tills purpose, the canonical boundary-value problem of surface-wave propagation guided by the planar interface of a rugate filter and a homogeneous medium with negative pernlittivity was solved numerically. Multiple Fano waves with different phase speeds and linear polarization states are guided by the interface, even when the magnitude of the pernlittivity of the partnering medium is less than the