A new, two-step scheme for the calculation of complex propagation constants in planar multilayer waveguides is presented. In the first step, by introducing a 'Mode function', a fast determination of an approximate value of the complex propagation constant for a chosen waveguide mode is found. In the second step, in which a fast root-finding algorithm is used, the precise value of the propagation constant is calculated. The result is a significant speeding up of the computational process in comparison to traditional methods of determining complex propagation constants. Implemented in Turbo Pascal Version 5.5 on an MS-DOS AT personal computer with co-processor and 10 MHz clock frequency, the propagation constant of a four layer channel waveguide with absorbing layers can be computed, using the effective index method, in 4 seconds after which the field profiles can be presented within a few seconds.

Date Published: 1 March 1992
PDF: 8 pages
Proc. SPIE 1603, Education in Optics, (1 March 1992); doi: 10.1117/12.57889

Published in SPIE Proceedings Vol. 1603:
Education in Optics
Gregory B. Altshuler; Brian J. Thompson, Editor(s)