Abstmct-AGaussian beam of light propagating through a quadratic phasized so-called horn geometries in which the guide lenslike medium remains Gaussian, even if all of the parameters of the width is varied rather than its thickness [71-[15]. a few medium vary along the propagation path. Exact numerical techniques are described for investigating the propagation of Gaussian beams in oractical taDered fiber-ontical waveguides. Solutions are obtained for have been [I6] 9 [171-other film coupler designs more complex taper geometries