New fluoroindate glass compositions

Abstract

The limits of glass formation of new fluoroindate glass compositions have been determined for the basic systems InF3–BaF2–GdF3−20ZnF2−20SrF2–2XFn where × = Na, La and InF3–BaF2−20ZnF2−20SrF2−2GdF3–XFn, where × = Ca and Y. The incorporation of small amounts of GaF3 and/or GdF3 increases strongly the thermal glass stability. All the fluoroindate compositions studied are highly transparent in the mid-infrared range; their transmission edge is shifted beyond 7 μm and the theoretical attenuation coefficient, extrapolated at the CO laser wavelength emission, is typically α = 100 dB/km. Large bulks and preforms have been prepared allowing the drawing of optical fibers.