Optical analysis of infrared spectra recorded with tapered chalcogenide glass fibers
Résumé
Infrared fiber evanescent wave spectroscopy (FEWS) spectra of water–ethanol mixtures are recorded and recon- structed thanks to a causal dispersion analysis technique. The complete expression of the complex reflection coefficients was used to determine the transmitted signal. The problems of shifting peaks or overlapping absorption bands from different chemical are well addressed. The effect of several parameters on the absorbance, such as the length of im- mersion and the diameter of the fiber probe have been calculated and fit well with experimental data. More generally, the agreement between experimental and calculated spectra suggest the presented analysis technique is more accurate than other current analysis techniques.