Analysis of fluorinated polymide waveguide directional couplers

Analysis of optical properties of fluorinated polyimide waveguide directional couplers is presented. An algorithm based on the transverse operator method is developed. The longitudinal section electric modes and longitudinal section magnetic modes of a corresponding dielectric stratified waveguide have been taken as the basis eigenfunctions. This allows a more rapid convergence in terms of modes. The number of eigenmodes used in this analysis does not depend on the multidielectric structure. The dispersion characteristics of this type of coupler have been calculated by using an equivalent multidielectric waveguide. The coupling length, coupling ratio and the polarization as functions of the coupler parameters are evaluated. The obtained results are compared with the published theoretical and practical data. The comparison shows that the used method has an excellent accuracy.