New progresses in transparent rare-earth doped glass-ceramics

Recent advances in rare-earth doped transparent fluoride glass-ceramics wit h high crystallisation level (90%) are reported. The first stages of the de vitrification process have been studied by X-ray scattering and their precu rsor signs observed by Raman spectroscopy. Transmission Electron Microscopy and X-ray microanalysis have also been used to measure the composition flu ctuations inducing the spinodal decomposition responsible for the devitrifi cation of this family of glasses. The optical spectroscopy of the erbium io n in the glass-ceramics shows crystal-like spectra, A reduction of inhomoge neous linewidth by a factor of 2 is observed between glass and glass-cerami c on different transitions resulting in an increase of the maximum cross-se ctions. The lifetime of the different measured levels is kept constant or i ncreased by the ceramming process. (C) 2001 Elsevier Science B.V. All right s reserved.