Glasses from lithium-aluminum-phosphate system doped with rare-earth oxides were studied. The following molar oxide composition was proposed: 17.88 Li₂O 8.93 Al₂O₃ 6.31 BaO 1.27 La₂O₃ 63.72 P₂O₅ 1.89 RE₂O₃, RE= Tb, Eu.

The glass was melt in an electrical furnace equipped with superkanthal heating resistance, in alumina crucibles, at 1250^oC, for minimum 2 hours. In order to improve the optical properties of the final glass a special device was used, consisting in a mechanical device equipped with alumina stirrer for mixing the melt. The rotation speed was varied between 100 and 500 rot/min. The glass was casted in graphite mould and then annealed in an electrical furnace with kanthal heating wire. The glass samples were annealed at the high annealing temperature for minimum 4 hours in order to obtain improved properties.

The light transmission, structure and homogeneity of the obtained glass were characterized by ultraviolet-visible (UV-Vis) spectrophotometry and scanning electron microscopy–energy dispersive X-ray (SEM-EDX) analysis, respectively. Transmission in the visible range was found to be above 90% and the chemical homogeneity was satisfactory.

The optical quality of the glass was enhanced by stirring the melt so that the cords and threads were much more reduced in the glass. The number and dimension of bubbles were minimized by the selection of an appropriate melting-refining thermal program, based on a proper selection of the temperature, duration, type and speed of stirring.