FLUORINE AND PHOSPHATE OPTICAL GLASS WITH ANOMALOUS POSITIVE PARTIAL DISPERSION AND ITS PROCESS OF PRODUCTION

摘要

A fluorine and phosphate optical glass on the basis of Mg(PO3)2, Ca(PO3)2, Ba(PO3)2, Al(PO3)3, MgF2, CaF2, SrF2, AlF3, BaO and SrO presents a refractive index ne between 1.515 and 1.546, an Abbe coefficient ωe between 75.8 and 77.4 and a positive anomalous partial dispersion value Δωe between 14.85 and 15.15. The glass is composed of (in atoms-%): 2.4-2.7 Mg, 4.5-4.9 Ca, 15.19-17.6 Sr, 20.2-22.3 Ba, 5.6-6.2 Al, 8.8-9.7 P, 22.0-24.3 F and 15.7-17.4 O. Improved physico-chemical parameters, such as coefficient of linear expansion, transformation temperature Tg, density$(1,3)$, Knoop-hardness HK, among others, are given. Finally, a process for producing this optical glass is disclosed.