Beam propagation in tapered quadratic index waveguides: Numerical solutions

Abstract
A Gaussian beam of light propagating through a quadratic lenslike medium remains Gaussian, even if all of the parameters of the medium vary along the propagation path. Exact numerical techniques are described for investigating the propagation of Gaussian beams in practical tapered fiber-optical waveguides. Solutions are obtained for off-axis beams in tapers which in general may also have quadratic radial loss variations.