Modal characteristics and cutoff conditions of a hypocycloidal waveguide with chiral media in the core and the cladding

Abstract

The characteristic equations and cutoff conditions for a hypocycloidal waveguide with chirality in the core and cladding have been derived for zero order modes using the strong guidance condition. Emphasis has been made mainly on the field cutoff condition. It is found that the cutoff condition of the waveguide with a chiral core and the chiral cladding is the same as that of a waveguide with a chiral core and a dielectric cladding. It is seen that the presence of the chirality in the proposed waveguide splits every mode into two modes. This implies that, the left handed and right handed modes merge into a single mode when the chiral admittance is zero. We also find that the cutoff core radii of right handed modes decrease with the increase of chiral admittance but the cutoff core radii of the left handed modes increase in magnitude. These properties can be applied in the design of a mode converter.