Inverse scattering designs of dispersion-engineered single-mode planar waveguides

Abstract

We use an inverse-scattering (IS) approach to design single-mode waveguides with controlled linear and higher-order dispersion. The technique is based on a numerical solution to the Gelfand-Levitan-Marchenko integral equation, for the inversion of rational reflection coefficients with arbitrarily large number of leaky poles. We show that common features of dispersion-engineered waveguides such as trenches, rings and oscillations in the refractive index profile come naturally from the IS algorithm without any a priori assumptions. Increasing the leaky-pole number increases the dispersion map granularity and allows design of waveguides with identical low order and differing higher order dispersion coefficients.