| 摘要 |
<p>PURPOSE: Fluorophosphate glass, a glass material for press molding, an optical device blank, an optical device, and their manufacturing methods are provided to improve thermal stability with maintaining a high refractive index and to inhibit the volatility of glass. CONSTITUTION: Fluorophosphate glass comprises a cation comprising 20 - 45 cation% of P^5+, 15-35 cation% of Al^3+ and 20-50 cation% of Ba^2+, and an anion comprising 20 - 50 anion% of F^- and 50 - 80 anion% of O^2-. The molar ratio of O^2-/P^5+ is 3.5 or greater, the molar ratio of Al^3+/P^5+ is 0.45 or greater, the Abbe number (?d) of the glass is 66 or greater, and the refractive index (nd) of the glass satisfies the relation represented by nd >= 2.0614-0.0071 x ?d. The liquid temperature of the glass is 900°C or less, and theΔPg,F of the glass is 0.015 or greater.</p> |
