The properties of modes in an asymmetrical planar chiral-anisotropic dielectric optical waveguide

Modes in an asymmetrical planar chiral-anisotropic dielectric optical waveguide are investigated. Mode dispersion characteristics and field distributions are calculated. Polarization properties of the modes are analyzed. It is demonstrated that mode fields have the elliptical polarization which is nonuniform over the waveguide cross section. The fields are thoroughly studied at the spectral points where approximate dispersion curves cross; i.e., modes are expected to be degenerate. The fine structure of the dispersion characteristics is analyzed in the vicinity of these points. It is found out that, in the above regions, the dispersion curves approach each other rather than cross, i.e., quasi-degeneration rather than degeneration is observed. Simultaneously, the right-hand elliptical mode polarization is transformed into the left-hand one and vice versa.