Fluorophosphate optical glass

Abstract

An optical glass has refractive index nd greater than 1.59, Abbe number υd greater than 67, low photoelastic coefficient, good chemical stability and excellent grinding property. Fluorophosphate optical glass contains, by cation percentage contents, 30-40% of P5+, 12-20% of Al3+, 30-40% of Ba2+, 1.3-12% of Ca2+, 1-10% of Sr2+, 0-5% of La3+, 0-6% of Gd3+, 0-10% of Y3+, and contains, by anion percentage contents, 25-40% of F+ and 60-75% of O2−. The optical glass is applicable to the manufacturing methods such as high precision molding, secondary hot molding and cold working, in order to produce optical elements like high-performance sphere, aspheric surface, plane lens, prism and raster.

Description

technical field [0001] The invention relates to a fluorophosphate optical glass, in particular to a fluorophosphate optical glass with relatively high refractive index, low dispersion, low photoelastic coefficient, good chemical stability and processing performance. Background technique [0002] Fluorophosphate optical glass is suitable as a lens material for eliminating high-order chromatic aberration in optical design due to its low dispersion and special dispersion. In fluorophosphate optical glass, low dispersion is usually accompanied by low refractive index, which is not suitable for making large diopter lenses. The existing low-dispersion fluorophosphate optical glass with a relatively high refractive index (nd>1.59) often has problems such as insufficient chemical stability, thermal stability and processing performance. [0003] Japanese Patent Laid-Open No. 2-124740 discloses a low-dispersion high-refractive index fluorophosphate optical glass, but this glass ha...

AI Technical Summary

Problems solved by technology

Existing low-dispersion fluorophosphate optical glasses with a relatively high refractive index (nd>1.59) often have problems such as chemical stability, thermal stability, and insufficient processing performance.

[0003] Japanese Patent Laid-Open No. 2-124740 discloses a low-dispersion high-refractive-index fluorophosphate optical glass, but the thermal stability of this glass is poor, the glass has a high liquidus temperature, and crystallization and streaks are prone to occur during production.

[0004] Chinese patent application 201110129548.2 discloses a fluorophosphate optical glass with better chemical stability, but the refractive index of the glass is insufficient (nd is lower than 1.58)

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