Infrared chalcogen glasses: chemical polishing and fibre remote spectroscopy

Inorganic vitreous polymers based on the combination of the chalcogen eleme nts Se, Te and As are investigated on account of their unique transparency in the infrared spectral domain leading to applications in night-vision sys tems as well as in IR remote fibre spectroscopy. An original procedure of c hemical polishing using a congruent dissolution process of the glass is dev eloped in order to produce outstanding optical quality surfaces. The same m ethodology is applied to produce tapered chalcogen glass fibres used as IR evanescent wave chemical sensors. In reducing the fibre diameter by chemica l etching, a significant improvement in the sensitivity of the optical sens or operating in the 2 to 12 mum spectral region is observed. This original optical configuration is applied to some in situ chemical or biological ana lysis. (C) 2001 Elsevier Science Ltd. All rights reserved.