A method for analyzing guided modes of doublecore step index dielectric waveguides with arbitrary cross-sectional shape and index difference between the cores is presented. It is based on the null field method and is formulated in rigorous vectorial form in terms of the transversal part of the magnetic field. A novel S-A classification of guided modes in dielectric waveguides which possess some kind of symmetry is introduced. Circular cores case as the canonical example of a fiber with the "rectangle" symmetry is worked out. It shows the accuracy and usefulness of the method and provides comprehensive characterization of S-A modes in such fibers. Analysis of the directional coupler performance in terms of introduced modes is also presented.

Date Published: 10 November 1986
PDF: 9 pages
Proc. SPIE 0670, Optical Fibres and Their Applications IV, (10 November 1986); doi: 10.1117/12.938960

Published in SPIE Proceedings Vol. 0670:
Optical Fibres and Their Applications IV
Ryszard S. Romaniuk; Mieczyslaw Szustakowski, Editor(s)