Heavy lanthanum flint glass and its preforms, optical components and optical instruments

Abstract

The invention discloses a heavy lanthanum flint glass and its preform, optical element and optical instrument. The heavy lanthanum flint glass contains by weight %: SiO 2 : 12‑30%, La 2 o 3 : 10‑25%, TiO 2 +Nb 2 o 5 +WO 3 +Bi 2 o 3 : 10.5‑40%, RO: 20‑35%, the RO is one or more of BaO, CaO, MgO and SrO, ZrO 2 : 0.5‑10%, where (SiO 2 +La 2 o 3 +ZrO 2 ) / TiO 2 is 0.75‑6.5. The glass has a refractive index (nd) of 1.86‑1.92 and an Abbe number (vd) of 25‑30, which can meet the optical properties required by precision instruments, and has excellent anti-devitrification performance and low temperature coefficient of refractive index, which can effectively reduce Thermal aberration caused by small temperature differences.

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 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. 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 components, ...

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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