The present invention provides an optical glass, containing, in % by weight on an oxide basis, 30 to 50% of P 2 O 5 , 18 to 43% of BaO, 2 to 12% of B 2 O 3 , 1.4 to 5% of Al 2 O 3 , more than 0 to 6% of Li 2 O, more than 0 to 9% of La 2 O 3 , 0.1 to 8% of MgO, 0 to 10% of CaO, 0 to 15% of SrO, 0 to 5% of ZnO, 0 to 7% of Gd 2 O 3 , and 0 to 3% of SiO 2 , and having optical constants of a refractive index n d of 1.59 to 1.63 and an Abbe number ν d of 63 to 68.
1. An optical glass, comprising, in % by weight on an oxide basis,
30 to 50% of P 2 O 5 ,
18 to 43% of BaO,
2 to 12% of B 2 O 3 ,
1.4 to 5% of Al 2 O 3 ,
more than 0 to 6% of Li 2 O,
more than 0 to 9% of La 2 O 3 ,
0.1 to 8% of MgO,
0 to 10% of CaO,
0 to 15% of SrO,
0 to 5% of ZnO,
0 to 7% of Gd 2 O 3 , and
0 to 3% of SiO 2 ,
wherein the optical glass has a refractive index n d of 1.59 to 1.63 and an Abbe number ν d of 63 to 68.
2. The optical glass according to claim 1 , wherein the refractive index n d is 1.59 or more and the Abbe number ν d is 66 or more.
3. The optical glass according to claim 1 , wherein the refractive index n d is 1.62 or more and the Abbe number ν d is 63 or more.
4. The optical glass according to claim 1 , wherein the optical glass has a viscosity (η LT ) at a liquid phase temperature of 6 dPa·s or more.
5. The optical glass according to claim 4 , wherein the viscosity (η LT ) at the liquid phase temperature is 12 dPa·s or more.
6. The optical glass according to claim 1 , wherein La 2 O 3 is included in an amount of from 0.5% to 9% in % by weight on the oxide basis.
7. The optical glass according to claim 1 , wherein La 2 O 3 is included in an amount of from 1% to 9% in % by weight on the oxide basis.
8. The optical glass according to claim 1 , wherein La 2 O 3 is included in an amount of from 1% to 4% in % by weight on the oxide basis.
9. The optical glass according to claim 1 , wherein Li 2 O is included in an amount of from 0.1% to 6% in % by weight on the oxide basis.
10. The optical glass according to claim 1 , wherein Li 2 O is included in an amount of from 0.5% to 5% in % by weight on the oxide basis.
11. The optical glass according to claim 1 , wherein CaO is included in an amount of from 0.5% to 9% in % by weight on the oxide basis.
12. The optical glass according to claim 1 , wherein SrO is included in an amount of from 0.1% to 10% in % by weight on the oxide basis.
13. The optical glass according to claim 1 , wherein ZnO is included in an amount of from 0.3% to 4% in % by weight on the oxide basis.
14. The optical glass according to claim 1 , wherein Gd 2 O 3 is included in an amount of from 0.5% to 5% in % by weight on the oxide basis.
15. The optical glass according to claim 1 , wherein SiO 2 is included in an amount of from 0.1% to 2.5% in % by weight on the oxide basis.
16. The optical glass according to claim 1 , wherein La 2 O 3 is included in an amount of from 1% to 4%, Li 2 O is included in an amount of from 0.5% to 5%, CaO is included in an amount of from 1% to 7%, SrO is included in an amount of from 0.2% to 7%, ZnO is included in an amount of from 0.7% to 3%, Gd 2 O 3 is included in an amount of from 1% to 3%, and SiO 2 is included in an amount of from 0.3% to 2%, in % by weight on the oxide basis.