<title>Chalcogenide glasses and fibers for applications in medicine</title>

Abstract

Chalcogenide glasses based on suplhides and selenides are very promising materials for various photonic applications, particularly for applications in medicine. Most of current optical fibers have been developed form ultrapure silica. While silica glasses are suitable for optical components in telecommunications they exhibit high losses beyond 2 micrometers - a wavelength range important for clinical practice. Thus special glass materials 9from which fibers could be drawn) should be developed for optical power transmission beyond 2 micrometers . The investigation and preparation of vitreous materials that include sulphide, selenide and selenide- tellurite glass systems together with fluoride and heavy metal oxide glasses on the base of ZrF<SUB>4</SUB>, HfF<SUB>4</SUB> and GeO<SUB>2</SUB>, TeO<SUB>2</SUB>, PbO, respectively are being pursued in our laboratory. This research is aimed at the development of both passive and active (rare-earth doped) optical fibers. In this contribution we concentrate on the doping of chalcogenide glasses by rare earth elements (Er, Pr, Nd). Although the major role of these glasses is assumed in the development of laser power delivery systems for applications in surgery, dentistry, dermatology and ophthalmology, they can equally be used for the diagnostics of human tissues. An example of colon tissue autofluorescence will be given.