Simulating and Fabricating Chalcogenide-based Waveguides for Agro-Environmental Applications

Agriculture challenges to reduce its environmental impact and to improve control over agricultural crops of agriculture are numerous. We develop here an optical integrated probe as potential answer to some detection challenges, based on a RIB chalcogenide waveguide. Early results have shown that the fabrication process induces sidewall roughness potentially altering the sensitivity of the probe. The numerical tool used here implements an approximation allowing to take into account sidewall roughness on propagation losses. This code is based on finite element method. Results show that sidewall roughness have a higher impact on losses for thin waveguides. Additionally, etching tests have been carried out to investigate the impact of oxygen concentration in the etching chamber over the quality of the sidewall. Results show that the more oxygen, the more important the roughness of the sidewall.