| 摘要 |
A glass consists essentially, in per cent by weight, of: Nb2O5 with or without Ta2O5, 5-40, at least 90% of the Nb2O5 and Ta2O5 aggregate being Nb2O5; BaO, 15-45; SiO2, 25-40, up to 30% of the SiO2 being replaceable by B2O3; La2O3, 0-36; ZnO and/or CdO, 0-10; Na2O and/or K2O and/or Ll2O, 0-5; TiO2 and/or ZrO2 and/or HfO2 and/or ThO2, in aggregate not more than 5; CaO and/or SrO, 0-15; the glass is substantially free of lead. The refractive index of the glass is at least 1-65. It may be used as core glass in fibre-optics structures, and in prisms.
|
