Index matching in multilayered organic waveguides

Index matching of guided modes in birefringent multilayered organic waveguides opens new prospects for the design of mode coupling and mode switching devices. We demonstrate index matching of guided modes in two multilayered structures, in (a) a PTCDA-Alq₃-PTCDA three-layer and (b) a PTCDA-Alq₃effective medium multilayer waveguide. The optical waveguides were grown on a Pyrex substrate by organic molecular beam deposition. The occurrence of index matching was investigated both experimentally by measuring the effective refractive index dispersion of transverse electric and magnetic modes using them-line technique and theoretically by modelling the index dispersion with a transfer matrix algorithm.