Optical glass

Abstract

The invention provides optical glass without containing fluorine, phosphorus or tantalum. The optical glass is high in chemical stability, excellent in crystallization property and high in transmittance. The optical glass comprises the following components in percentage by weight: 10-40% of SiO2, 5-20% of B2O3 (not including 20%), La2O3 more than 5% but less than or equal to 15%, and 20-50% of BaO. According to the reasonable formula design, the optical glass lambda 80 is less than or equal to 360nm when the optical glass has the refractive index of 1.62-1.70 and the abbe number of 50-60, the upper limit of a devitrification temperature of the glass is below 940 DEG C, and the water resistance stability DW of the glass is over class 1. Moreover, the optical glass does not contain fluorine, phosphorus or tantalum, and has excellent chemical stability, crystallization property and transmittance.

Description

technical field [0001] The invention relates to an optical glass with a refractive index of 1.62-1.70 and an Abbe number of 50-60, as well as a glass preform and an optical element made of the optical glass. Background technique [0002] In recent years, with the development of optoelectronic systems, optical glasses with a refractive index of 1.62-1.70 and an Abbe number of 50-60 have been widely used. In addition to the optical properties that need to be set, optical glass must also have excellent internal quality, such as streaks, bubbles and inclusions. Optical glass with a large amount of fluorine or phosphorus is prone to streaks and fluctuations in optical constants due to the volatility of fluorine and phosphorus during the melting process. In the manufacturing process of optical glass, platinum or platinum alloy is usually used as a melting tool. When the glass component contains fluorine or phosphorus, the corrosion of platinum is relatively large, resulting in in...

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Problems solved by technology

[0003] CN1303024C discloses an optical glass with a refractive index of 1.60-1.68 and an Abbe number of 40-65. The glass component contains 5-10 mol% of phosphorus and 15-35 mol% of fluorine, and the streaks and intrinsic quality of the glass are not easy control

CN101643314A discloses an optical glass with a refractive index of 1.55-1.62 and an Abbe number of 55-62. The glass component contains 35-45wt% P 2 o 5 , glass volatilization is serious, streaks and intrinsic quality are poor

[0005] CN1323281A discloses an optical glass whose refractive index is above 1.65-1.73 and whose Abbe number is 50-60. The glass component contains a certain amount of Ta 2 o 5 , due to Ta 2 o 5 Expensive, will greatly increase the production cost of glass and reduce its competitiveness

[0007] Optical glass with a refractive index of 1.62-1.70 and an Abbe number of 50-60. In the absence of phosphorus, fluorine and tantalum, the glass component contains a certain amount of alkaline earth metals or alkali metals. The chemical stability of the glass is poor. Good for subsequent processing

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