Recovery of refractive-index profiles of planar graded-index waveguides from measured mode indices : an iteration method

An iteration method for calculating refractive-index profiles of graded-index waveguides from measured effective indices is presented. The refractive-index profiles recovered from the effective indices for the exponential function indicate that the accuracy of this method is better than ±10−4. We apply this method to Ti in-diffused Fe2O3–LiNbO3 and two-step ion-exchanged glass waveguides and obtain a good agreement between the theoretical and the experimental values.