Remote analysis using IR glass fibers

The good performances of Te-As-Se based glass fibers allow using them in evanescent wave spectroscopy. These IR optical fibers have been developed in order to optimize their response when they are used as evanescent wave chemical sensors. The diameter of the sensitive part of the fiber can be reduced by tapering the fiber during the drawing process or by chemical polishing. Zn using a FTIR spectrometer associated with a MCT detector, it was possible to evaluate the sensitivity of such sensor. The influence on the analyzed liquid IR signatures has been tested versus the fiber diameter, the immersed fiber length and the liquid concentration The high flexibility of thin fibers allows the achievement of a detection probe that enables to follow in situ, real-time and on-fine chemical or biological reaction.