Tapered TeX glass optical fibers for remote IR spectroscopic analysis

Infrared TeX fibers operating in a wide wavelength region have various potential uses in the short distance area such as laser power delivery, remote temperature monitoring and chemical analysis. TeX glass fibers with a minimum attenuation of 0.5 dB/m in the 7 - 10 micrometer range have been obtained. A plastic coating protects these fibers from external environment and improves their mechanical properties. Remote spectroscopy using mono-index fiber is one of the most promising applications. This new technology allows the identification and in situ analysis of many substances such as oils and fertilizers, which have their fingerprint in the 2 - 13 micrometer domain. The detection efficiency using evanescent wave absorption has been studied as a function of the fiber's diameter. It is found that the sensitivity increases very rapidly when the fibers' diameter decreases. The possibility of detecting very low concentrations has been tested by using TeX tapered fibers.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.