Design of corrugated waveguide filters by Fourier-transform techniques

A new, approximate, corrugated waveguide filter design method is developed for thin-film optical waveguides. The method determines both the corrugation period and depth measured along the guide´s surface, given a specification of the filter´s reflection coefficient. The design technique is based on a combined effective index approach and Fourier transform, inverse-scattering theory for one-dimensional, dispersionless, dielectric media. Use of the general technique is illustrated by the design of two corrugated waveguide filters. The design results are compared with those obtained using the first Born approximation, nonlinear renormalization, and the exact Gel´fand-Levitan-Marchenko method for two component inverse-scattering systems