NEW YB-DOPED FLUORIDE PHOSPHATE LASER GLASS-STRUCTURAL INVESTIGATIONSUSING PROBE IONS

Various probe ions have been employed to improve the performance of Yb -doped laser glasses. Lanthanide ions similar to the Yb3+, e.g. Nd3+, EU3+ and Gd3+, are sensitive to their site surroundings and that is wh y they are useful for obtaining the structural information needed to t ailor the laser host matrix. A new promising laser glass based on thes e investigations has been developed. We assume that the favorable lase r properties of this glass can be explained by formation of [Yb(PO4)3] -clusters which are nearly isolated from the main part of the network. The electron-phonon coupling in optimized fluoride phosphate glasses with tetrahedral anions may efficiently depopulate the terminal laser level.