Oxyfluoride glass-ceramics are obtained when a precise thermal treatment is applied to a precursor glass. This thermal treatment causes that fluoride nanocrystals precipitate in the vitreous matrix. X-ray diffraction measurements have been performed and reveal that two phases coexist in the glass-ceramic. One is vitreous and has an oxyfluoride composition and the second one is crystalline and provides a fluoride environment. In fact, the macroscopic properties of the glass-ceramic are characteristic of the aluminosilicate glassy phase except the optical properties of the rare-earth (RE) ions, which are characteristic of low-phonon energy fluoride crystals. The fluoride nanocrystals have low-phonon energy and, as a consequence, the probability of nonradiative relaxation processes is expected to be low, giving place to longer excited state lifetimes than in the oxyfluoride precursor glass. A very efficient IR to visible upconversion process is reported in Ho³⁺ doped glass-ceramics. Three strong emission bands in the primary color components, red, green, and blue give place to an intense white emission light, which is observed by the naked eye under IR excitation at 750nm. The excitation mechanism of this efficient upconversion emission is studied and it was found to be due to a photon avalanche process.

Finally, laser action in Nd³⁺ doped gass-ceramics has been studied. A relatively low pump threshold of about 18 mJ was detected. Losses due to UV and visible upconverted emission inside the laser cavity have been observed.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/3707 must be provided.

1. Analysis of the optical properties of Pr³⁺-Yb³⁺ ions in codoped transparent oxyfluoride glass ceramics. Application for 1300 nm optical amplifier