STUDIES ON THE PREPARATION AND PROPERTIES OF ALF3-BASED RARE-EARTH FLUORIDE GLASS

AlF3-REF(3)-AEF(2)(RE: rare earth, AE: alkali earth) system fluoride glasses were pre pared by quenching melts. The glass forming region of ALF(3)-NdF3-(Mg0.25Ca0.25Sr0.5Ba0.25)F-2 system was determined. Effects of AE and RE fluoride on the glass forming ability and thermal properties of the system have been discussed. The IR cut-off wavelength of: AlF3-REF(3)-AEF(3) glass is about 7 mu m. This system has many advantages, such as low refractive index, high Abbe number, high T-g. and T-e-T-g values, and good chemical durability, etc. This is a-kind of new excellent ultra-low loss IR optical fiber and IR optical material.