Desenvolvimento de um sensor de fibras ópticas de sulfeto de hidrogênio baseado em redes de Bragg e Filmes Finos

Abstract

Hydrogen sulfide is currently a major concern in oil industry, since it causes irreversible damage to both human resources employed in the activity (even leading to death) as well as to production itself, causing corrosion of pipelines and structures in oil processing or extrrcing plants. The objective of this work is to develop a new technique for measurement of hydrogen sulfide gas, using a sensor based on fiber Bragg gratings, known as optical fiber sensorsand thin films. To carry out the measures fiber Bragg gratings-based sensing methodologies and deposition of nanometric thin films sensitive to the gas in question will be employed. Sensitive films are deposited on fibers which had their shells previously removed and Bragg gratings inscribed in order to achieve responsiveness to hydrogen sulfide in the range of part per million. A study of the possible causes of sensibility in the sensor was also peformed i.e., effects generated by films with subwavelength thickness on the optical response of sensor, device’s optomechanical characteristics, as well the chemical composition of deposited films. Finally, the characteristics of the built sensor are shown. These can measure on a tour of the order of tens of parts per million and with a sensitivity of 1 pm / ppm, a value comparable to the sensors FBGs existing.