Amélioration de performance du capteur environnemental à fibre optique

Abstract

Water pollution can have serious consequences on both human health and the environment, so it is essential to prevent and mitigate these impacts. This major issue necessitates the development of novel technologies to continually and in situ manage water quality. Optical methods are one of the techniques used to detect and monitor water quality; they are used to detect pollutants in water by analyzing a light beam after passing through the medium to be analyzed. This technique is based on the measurement of intensity, absorption, refractive index, and other parameters. Methyl Orange was chosen as a model pollutant in the monitoring of polluted water in our experiment because it is commonly used as an acid-base indicator and has multiple interpretations. The geometry of the fiber is changed into a U-shaped design for testing Methyl Orange (MO) at the laboratory of applied optics to enhance the sensitivity of the optical fiber sensor (FOS). This design allows for a larger interaction between the evanescent field and the surrounding medium, which has better sensitivity compared to a straight one, making it more suitable for accurately monitoring MO concentration changes in distilled water.

The main objective of this thesis is to achieve an optical fiber sensor working in the visible range for detecting pollutants in water, and develop a technique based on the analysis of a light beam after passing through the medium to be analyzed which can measure parameters such as intensity, absorption, refractive index, and so on.