| The propagation of electromagnetic waves in a cylindrical structure partially filled with chiral material was examined. The general waveguide structure contains a cylindrical shell of chiral loss less material surrounded by two distinct achiral homogeneous and isotropic loss less materials. Both the unshielded and shielded cases are considered. Three limiting cases of the general shielded structure, including the completely chiral filled, chiral rod loaded and chiral lined circular waveguides, are analyzed. Also, two limiting cases of the general unshielded structure are considered, including the chiral rod waveguide and the achiral rod waveguide in an unbounded chiral medium.;The characteristic equations for the structures noted above are derived, and the nature of propagating modes which can exist in the structures are understood by examining the ratio of RHCP and LHCP fields inside the chiral region. Examples of the dispersion diagrams are given. The effect of chirality, the relative ratios of the boundary radii and the permitivities of the achiral regions on the mode cutoffs are examined. Also, examples of the waveguides fields are presented which show the RHCP and LHCP field components inside the chiral medium.;Distinct classes of chiral dielectric waveguide are defined depending on the relative permittivity of the surrounding achiral regions. In one special class of waveguides, the impedance of the chiral material is matched to the impedance of the achiral material. A significant reduction in the dispersion relation is noted. For some matched impedance unshielded waveguides, the waveguides fields in the chiral material consists of a pure circular polarization. Finally, the normalized modal birefringence is presented and the effects of the achiral regions relative permittivity and the relative ratio of the boundary radii are discussed. The waveguide modal birefringence is always less than or nearly equal to the available birefringence of the host chiral medium. |
