OH-absorption in fluoride glass infra-red fibres

Abstract

The OH fundamental peak absorption at 2.87 μm has been reduced in fluoride fibres to less than 20 dB/km. By measuring the difference spectra between low and high peaks, the OH-peak shape has been measured over two orders of magnitude, and the results indicate that the optimum low-loss window occurs at 2.55 μm in these materials.