Abstract

Accurate methods for computing the modes of optical waveguides are needed both for design and testing of lasers and optical integrated circuits. In this paper, we present a method for making an accurate numerical calculation of the modes of optical waveguides [1]. It consists of enclosing the waveguide within a rectangle large enough to ensure that the fields of the guided modes of interest are zero at this boundary. The field is then expanded in a double Fourier series in which the sinusoidal basis functions are zero at the boundary. This expansion converts the scalar wave equation into a set of homogeneous linear equations for the Fourier coefficients. The eigenvalues and coefficients of the bound modes are then found by solving the matrix eigenvalue problem by use of the standard EISPACK programs.

© 1989 Optical Society of America