Heavy lanthanum flint glass and preform thereof, optical element and optical instrument

Abstract

The invention discloses a heavy lanthanum flint glass and a preform, an optical element, and an optical instrument. The heavy lanthanum flint glass is prepared from the following components in percentage by weight: 12 to 30 percent of SiO2, 10 to 25 percent of La2O3, 10.5 to 40 percent of TiO2+Nb2O5+WO3+Bi2O3 and 20 to 35 percent of RO and 0.5 to 10 percent of ZrO2, wherein the RO is one or more of BaO, CaO, MgO and SrO, and (SiO2+La2O3+ZrO2) / TiO2 is 0.75 to 6.5. The refractive index (nd) of the glass is 1.86 to 1.92 and the abbe number (vd) is 25 to 30; the heavy lanthanum flint glass can meet optical properties required by precision instruments and has the advantages of excellent anti-crystallization performance, low refractive index temperature coefficient and capability of effectivelyreducing thermal aberration caused by temperature difference.

Description

technical field [0001] The invention belongs to the field of optical glass, and in particular relates to heavy lanthanum flint glass and its prefabricated part, optical element and optical instrument. Background technique [0002] Heavy lanthanum flint glass with a refractive index (nd) of 1.86-1.92 and an Abbe number (vd) of 25-30 is widely used in lenses of precision optical instruments. However, the existing heavy lanthanum flint glass has a large temperature coefficient of refraction index. When it is applied in the fields of medical treatment, night photography, and integrated circuit lithography technology, the thermal difference caused by the large change of refraction index with temperature will affect the accuracy of the instrument. and accuracy are greatly affected. At the same time, some glass components added to increase the refractive index reduce the transmittance of the glass. In order to improve the imaging quality, it is necessary to make very thin glass co...

AI Technical Summary

Problems solved by technology

However, the existing heavy lanthanum flint glass has a large temperature coefficient of refraction index. When it is used in medical treatment, night photography, integrated circuit photolithography and other fields, the thermal difference caused by the large change of refraction index with temperature will affect the accuracy of the instrument. have a greater impact on accuracy

At the same time, some glass components added to increase the refractive index reduce the transmittance of the glass. In order to improve the imaging quality, it is necessary to make very thin glass components, which increases the difficulty of component manufacturing and leads to a higher defective rate.

In addition, the upper limit temperature of crystallization of the existing heavy lanthanum flint glass is relatively high, the stability of the glass is poor when processed at high temperature, and the thermal processing process is difficult

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