ESTIMATION OF DISPERSION PARAMETERS INVOLVING THE PETERMANN-II SPOT SIZE USING A GAUSSIAN-TYPE APPROXIMATION IN SINGLE-MODE GRADED-INDEX FIBERS

Based on a recently prescribed simple and novel approximation of the f undamental mode, we present analytic expressions for the Petermann II spot size, suitable for evaluating the dispersion parameters of single -mode graded-index fibers. With these expressions, we calculate the gr oup delay dispersion factor and also the normalized waveguide dispersi on coefficient. On comparison, our formulation is shown to be superior to the Gaussian approximation and predicts the parameters identically with the exact numerical techniques for step and parabolic index prof iles. (C) 1997 Society of Photo-Optical Instrumentation Engineers.