Infrared optical fibres based on chalcogenide glasses have been designed for evanescent wave spectroscopy. The sensitivity of the optical sensor is improved in tapering the sensing zone by chemical etching and the working optical domain of the system has been tested on a chloroform sample. This original remote sensor, based on the analysis of infrared signatures, has been applied to follow the fermentation process in cider fabrication as well as to detect and monitor a bacterial biofilm.
Des fibres optiques infrarouge a base de verres de chalcogenures ont ete effilees par un procede chimique pour realiser des analyses infrarouges deportees par absorption des ondes evanescentes. Le spectre du chloroforme permet de verifier la zone de travail de la fibre. Ce systeme est applique au suivi du processus de fermentation dans la fabrication du cidre et a la detection et au controle de biofilms bacteriens.