NEW GAUSSIAN-BASED APPROXIMATION FOR MODELING NONLINEAR EFFECTS IN OPTICAL FIBERS

The use of Gaussian field approximations enables simple analytical mod els to be derived for non-linear fibers and doped-fiber laser and ampl ifiers. A new Gaussian-based method is described that is as easy to us e as the standard Gaussian approximations, yet provides an rms error i n the confinement factor of only 1.1% for a wide range of matched-clad ding fibers. Similar accuracy is obtained for depressed-cladding fiber s. The new approximation is used to predict Raman gain in a typical ex perimental MCVD fiber and excellent agreement is obtained between theo ry and experimental measurements.