An analytical investigation of the dispersion characteristic of a lightguide with an annular core cross section bounded by two cardioids

With the use of the scalar field approximation, an analytical study has bee n made of a lightguide having a cardioidically distorted annular core cross section. Using appropriate new coordinates (xi, eta, z) and with the weak guidance boundary conditions, the modal characteristic equation has been de duced analytically. From this equation, the modal characteristic curves hav e been obtained for some low-order modes (v = 0). (C) 1999 John Wiley & Son s, Inc.