A comparative study of the modal characteristics and waveguide dispersion of optical waveguides with three different closed loop cross-sectional boundaries

Abstract

A comparative theoretical study of three optical waveguides with different core-cross sectional boundaries is presented. The boundary loops can be described by equation xN +yN = aN, where N takes the values 1, 2/3 and 4. For N = 1, we have a circular boundary (standard fiber), for N = 2/3, the boundary is a hypocycloid and for N = 4, the boundary is a Piet-Hein curve. An attempt has been made to determine how the modal characteristics and waveguide dispersion change as the circular shape is changed to the hypocycloidal shape and the Piet Hein shape. It is found that the Piet-Hein shape combines the desirable characteristics of the circular and the rectangular waveguides.