Analysis of absorbing and leaky planar waveguides: a novel method

We present a simple and general approach for analysis of absorbing and leaky waveguides. The real and imaginary parts of the propagation constant beta of a planar optical waveguide are obtained by evaluating a function, defined through the eigenvalue equation, in real beta. The applicability of the method is demonstrated for simple structures. To apply the method for arbitrarily graded inhomogeneous or multilayered structures we use a simple matrix approach to obtain the eigenvalue equation. The method is straightforward, accurate, and requires no iteration in the complex beta plane.