Agriculture challenges to reduce its environmental impact and to improve control overagricultural crops of agriculture are numerous. We develop here an optical integrated probe as potentialanswer to some detection challenges, based on a RIB chalcogenide waveguide. Early results have shownthat 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 sidewallroughness on propagation losses. This code is based on finite element method. Results show that sidewallroughness have a higher impact on losses for thin waveguides. Additionally, etching tests have beencarried out to investigate the impact of oxygen concentration in the etching chamber over the quality ofthe sidewall. Results show that the more oxygen, the more important the roughness of the sidewall.