| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide optical glass having a high refractive index and high transparency. <P>SOLUTION: The optical glass has a refractive index nd in the range of 1.945≤nd≤1.97, an Abbe numberνd in the range of 33≤νd≤36 and an internal transmittance of over 80% in 10 mm thickness for light at 410 nm wavelength, and is free from lead and arsenic. The glass contains the following components in amounts expressed in % of their cations: 35 to 46% of B<SP>3+</SP>, 25 to 35% of La<SP>3+</SP>, 6 to 14% of Ta<SP>5+</SP>, 6 to 13% of W<SP>6+</SP>, 1 to 7% of Zr<SP>4+</SP>, 0 to 5% of Gd<SP>3+</SP>, 0 to 4% of Nb<SP>5+</SP>, 0 to 4% of Y<SP>3+</SP>, 0 to 2% of Ba<SP>2+</SP>, and 0 to 2% of the sum of alkaline earth metal oxides. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
