Optical glass

Abstract

The invention provides an optical glass with excellent internal quality and excellent transmittance, its composition is represented by weight percentage, and its cation contains: Si 4+ : Greater than 0 but less than or equal to 6%; B 3+ : 8‑20%; La 3+ : 40‑60%; Gd 3+ : 20‑35%; Y 3+ : 2‑15%; Nb 5+ : 0‑8%; its anion contains F ‑ and O 2‑ , where F ‑ / O 2‑ is 0.15-0.55. The present invention reduces the volatilization of F content through reasonable component design, and effectively controls problems such as streaks and optical constant fluctuations of the glass due to F volatilization; no Li is introduced into the glass components. + , reduce the corrosion of platinum utensils, and reduce the risk of inclusions. Through reasonable formula design, the optical glass of the present invention has excellent internal quality and transmittance while having a refractive index of 1.71-1.78 and an Abbe number of 52-58.

Description

technical field [0001] The invention relates to an optical glass, in particular to a high-refraction and low-dispersion optical glass, a glass preform and an optical element. Background technique [0002] For optical glass, the refractive index, Abbe number, and transmittance are its core optical characteristics. The refractive index and Abbe number determine the basic functions of glass. Optical glass with a refractive index of 1.71-1.78 and an Abbe number of 51-58 belongs to high refractive index and low dispersion optical glass. The application of this kind of high-performance glass in optical systems The length of the lens can be shortened and the imaging quality can be improved. [0003] In addition to the optical properties that need to be set, optical glass must also have excellent internal quality (stripes, bubbles and inclusions, etc.). In some cases, the internal quality of the glass depends on the composition of the glass. The optical glass with a large amount o...

AI Technical Summary

Problems solved by technology

[0004] CN101062833A discloses a precision molded optical glass with a refractive index of more than 1.70 and an Abbe number of more than 50, which contains 1-25% mole of Li 2 O, during the high-temperature melting process, the Li in the glass component + It is easy to corrode platinum or platinum alloy utensils, resulting in more platinum-containing foreign matter in the finished glass, resulting in a decline in the quality of the glass

At the same time, in the precision molding process, the mold is generally coated with a release agent containing carbon elements, containing Li + Li in the glass component + It is easy to react with the carbon element in the release agent to produce a rough opaque film layer on the glass surface, thus causing the surface of the glass element to be blurred

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