Finite element analysis of weakly guiding fibers with arbitrary refractive-index distribution

It is shown, with numerical examples, that fundamental quantities that characterize the guided modes of an optical fiber, such as propagation constant, field pattern, fraction of power in the fiber core, group delay, and waveguide dispersion, can be easily and accurately computed by a simple finite element method that incorporates an efficient recurrence algorithm for modeling the infinite cladding of the fiber. With this method, propagation characteristics of single-mode fibers with different refractive-index distributions are calculated and compared.