Refractive index characterization of waveguide channels using spectroscopic ellipsometry

Spectroscopic ellipsometry is applied to the characterization of UV patterned channel waveguides to obtain refractive index contrast and surface contraction. The waveguides were prepared with organic-inorganic di-ureasils hybrids modified with zirconium tetra-propoxide, processed as thin films in silica on silicon substrates. The channel waveguides were produced by direct writing using UV laser radiation. The application of multi-objective optimization in ellipsometric data analysis of the waveguides is presented. A comparison between single and multi-objective genetic algorithms indicates that the performance of the suggested method is higher. The increase in the refractive index of the channel waveguide due to UV exposure, relatively to the remaining of the film, was estimated to be 0.0003, and the surface ablation was 66mn, showing good agreement with experimental values reported in the literature.