Optical and structural investigation on rare-earth-doped aluminophosphate glasses

Aluminophosphate glasses belonging to the oxide system Li2O–BaO–Al2O3–La2O3–P2O5, un-doped and doped with rare-earth metal ions (Ce4+, Nd3+, Sm3+) were obtained by a wet non-conventional method. The influence of the doping ions on the optical properties of the phosphate glasses has been investigated in relation with structural features of the vitreous matrix. The optical behavior has been studied by ultra-violet–visible–near-infra-red (UV–VIS–NIR) spectroscopy, revealing electronic transitions specific for rare-earth ions. Structural information via optical phonons was provided by infrared (IR) absorption spectra in the range 400–4000 cm−1. Raman and fluorescence spectroscopy measurements have been performed. A strong fluorescence was observed in the visible spectrum, using 514.5 nm and 633 nm laser excitation.