Mode properties of optical fibers with lossy components by the propagating beam method.

The theory of optical fibers has been concerned mainly with propagation in lossless waveguides. Although real fibers are composed of core materials with extremely small absorption coefficients, they may have claddings and jackets with substantially higher losses. These components can in turn selectively attenuate certain higher-order guided modes. The propagating beam method utilizes configuration space solutions to a scalar wave equation to generate the mode propagation constants and eigenfunctions for a general class of weakly guiding fibers. This method has now been generalized to treat fibers with absorbing components such as claddings and jackets. It is now possible to compute with this generalized method both the mode attenuation coefficients and mode eigenfunctions for such fibers. Results are given for planar and circularly symmetric waveguides with lossy claddings and jackets.