Highly refractive optical glass with refractive indices >1.83 and Abbe numbers <25, and with very good chemical stability
AssigneeSchott Glaswerke
InventorsDanuta Grabowski, Ludwig Ross, Volkmar Geiler
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Abstract
A highly refractive optical glass (n.sub.d .gtoreq.1.83) with high dispersion (v.sub.d .ltoreq.25) and very good chemical stability at relatively low density (.delta..ltoreq.3.5 g/cm.sup.3) consists of (in weight percent) SiO.sub.2 19-25, Na.sub.2 O 7-10, K.sub.2 O 4-7, Cs.sub.2 O 0-12, Cao 0.5-2.0, BaO 9-15, TiO.sub.2 25-30, ZrO.sub.2 0-6, Nb.sub.2 O.sub.5 16-20, WO.sub.3 0-3, with Nb.sub.2 O.sub.5 :TiO.sub.2 =0.6-0.71.
Claims9
Highly refractive optical glass having a refractive index n.sub.d of 1.83-1.88, an Abbe number v.sub.d of 22-25 and a density of 3.0-3.5, characterized by the following composition (in wt.%):
- ______________________________________ SiO.sub.2 19-23.5 Na.sub.2 O 7-10 K.sub.2 O 4-6.5 Cs.sub.2 O 0.5-12 Na.sub.2 O + K.sub.2 O + Cs.sub.2 O 11.5-25.0 CaO 0.5-1.5 BaO 9-15 TiO.sub.2 25-28 ZrO.sub.2 2-6 Nb.sub.2 O.sub.5 16-19 Nb.sub.2 O.sub.5 :TiO.sub.2 0.64-0.68. ______________________________________
Dependencies are inferred from the claim text.