A SURFACE INTEGRAL-EQUATIONS METHOD FOR HOMOGENEOUS OPTICAL FIBERS AND COUPLED IMAGE LINES OF ARBITRARY CROSS-SECTIONS

Based on the surface integral equations, a method is developed to treat the propagation characteristics of homogeneous optical fibers of arbitrary cross sections in both the rigorous vectorial and the approximate scalar formulations. The surface integral equations are first formulated to relate the associated fields and their normal derivatives at the boundaries of dielectric cylinders. Then, the Green's function at cutoff is presented. The propagation characteristics of guided modes can then be determined by point-matching at such boundaries the normal derivatives for the scalar form or the four kinds of tangential fields (deduced from the associated fields and their normal derivatives) for the rigorous vector form. Numerical results of single and double waveguides with circular and rectangular cross sections are presented for both the vector and scalar forms.