Abstract: An optical glass includes, in percent by weight, 2-11% SiO2, 28-45% B2O3, 2-15% CaO, 3-18% ZnO, 1-8% ZrO2, 9-40% La2O3, 0.5-11% Gd2O3, 0-10% Y2O3, 0-3% Al2O3, at most 8% R2O, where R2O is selected from the group consisting of Li2O, Na2O and K2O, at most 20% R?O, where R?O is selected from the group consisting of MgO, CaO, SrO and BaO, 0-3% WO3, 0-2% Nb2O5, and 0-1% Sb2O3. The optical glass is free from environmental and human harmful components such as PbO and As2O3. The optical glass has a refractive index in the range of 1.66-1.72, an Abbe number in the range of 51-56, a liquidus temperature (LT) of at most 1000° C. and a raw material melting temperature of at most 1300° C. The optical glass is suitable for mass production, and is stable against devitrification during manufacturing of preforms and precision molding of lenses.

Abstract: An optical glass suitable for mold forming at a low temperature including, in percent by weight, 9-25 percent of P2O5, 1-20 percent of GeO2, 12-28 percent of Nb2O5, 1-7 percent of TiO2, 0-55 percent of Bi2O3, 0-38 percent of WO3, 0-3 percent of SiO2, 0-5 percent of B2O3, 0-2 percent of Al2O3, 0-5 percent of Li2O, 0-11 percent of Na2O, 0-5 percent of K2O, 0-3 percent of Ta2O5, 0-1 percent of Sb2O3, at most 13 percent of at least one R2O selected from the group consisting of Li2O, Na2O and K2O, and at most 15 percent of at least one XO selected from the group consisting of CaO, SrO, BaO and ZnO. The optical glass essentially contains no environmental and human harmful components, facilitates mass production and is stable against devitrification near its softening temperature.

Abstract: An optical glass includes, in percent by weight, 2-11% SiO2, 28-45% B2O3, 2-15% CaO, 3-18% ZnO, 1-8% ZrO2, 9-40% La2O3, 0.5-11% Gd2O3, 0-10% Y2O3, 0-3% Al2O3, at most 8% R2O, where R2O is selected from the group consisting of Li2O, Na2O and K2O, at most 20% R?O, where R?O is selected from the group consisting of MgO, CaO, SrO and BaO, 0-3% WO3, 0-2% Nb2O5, and 0-1% Sb2O3. The optical glass is free from environmental and human harmful components such as PbO and As2O3. The optical glass has a refractive index in the range of 1.66-1.72, an Abbe number in the range of 51-56, a liquidus temperature (LT) of at most 1000° C. and a raw material melting temperature of at most 1300° C. The optical glass is suitable for mass production, and is stable against devitrification during manufacturing of preforms and precision molding of lenses.

Abstract: An optical glass suitable for mold forming at a low temperature including, in percent by weight, 9-25 percent of P2O5, 1-20 percent of GeO2, 12-28 percent of Nb2O5, 1-7 percent of TiO2, 0-55 percent of Bi2O3, 0-38 percent of WO3, 0-3 percent of SiO2, 0-5 percent of B2O3, 0-2 percent of Al2O3, 0-5 percent of Li2O, 0-11 percent of Na2O, 0-5 percent of K2O, 0-3 percent of Ta2O5, 0-1 percent of Sb2O3, at most 13 percent of at least one R2O selected from the group consisting of Li2O, Na2O and K2O, and at most 15 percent of at least one XO selected from the group consisting of CaO, SrO, BaO and ZnO. The optical glass essentially contains no environmental and human harmful components, facilitates mass production and is stable against devitrification near its softening temperature.