Analytical study of the cutoff conditions and the dispersion curves of a waveguide with a cross-sectional shape resembling an ellipse compressed along the minor axis

Abstract

In this paper, we present an analytical study of the modal characteristics, cutoff conditions, and dispersion curves of a special type of an optical waveguide with a cross-sectional shape resembling all ellipse compressed along the minor axis (ECMI). Using the boundary conditions for the proposed waveguide under weak guidance, the cutoff equation and the modal characteristic equation have been obtained. From the cutoff equation, we find the number of modes propagating for the guiding region. Also, from the modal characteristic equation, we obtain the dispersion curves for some low-order modes.