REVIEW OF NUMERICAL AND APPROXIMATE METHODS FOR THE MODAL-ANALYSIS OFGENERAL OPTICAL DIELECTRIC WAVE-GUIDES

This paper reviews numerical and approximate methods for the modal ana lysis of general optical dielectric waveguides with emphasis on recent developments. Six groups of methods are reviewed, covering (1) the fi nite-element method, (2) the finite-difference method, (3) the integra l-equation method, (4) methods based on series expansion, (5) approxim ate methods based on separation of variables, and (6) methods that do not fit into the above groups, ranging from the specialized ones for a nalysing restricted classes of waveguides to the most general ones for analysing inhomogeneous, arbitrarily-shaped, anisotropic waveguides. Some suggestions with regard to the selection of methods for particula r applications are given.