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

Abstract

The invention discloses a heavy lanthanum flint glass and its prefabricated piece, optical element and optical instrument. The heavy lanthanum flint glass, by weight %, contains: SiO 2 : 12‑30%, TiO 2 +Nb 2 o 5 +WO 3 +Bi 2 o 3 : 10.5‑40%, B 2 o 3 : 0‑10%, where (SiO 2 +TiO 2 ) / (B 2 o 3 +Nb 2 o 5 ) is 1-30, the refractive index (nd) of the glass is 1.86-1.92, the Abbe number (vd) is 25-30, and the temperature coefficient of refraction is 2.4×10 ‑6 / °C below. The glass can meet the optical performance required by precision instruments, and has excellent anti-devitrification performance, low temperature coefficient of refractive index, and can effectively reduce 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. These heavy lanthanum flint glasses can meet the requirements of modern precision molding processes. However, the existing heavy lanthanum flint glass has a high temperature coefficient of refraction index. [0003] The refractive index of optical glass is a function of temperature, and the relationship between them is closely related to the composition and structure of the glass. When the temperature rises, the refractive index of the glass will be affected by two opposite factors. On the one hand, due to the temperature rise, the thermal expansion of the glass reduces the density and th...

AI Technical Summary

Problems solved by technology

[0004]In the optical instruments used in the fields of medical treatment, night photography, integrated circuit lithography technology, etc., the temperature of the operating environment of the optical lens will continue to increase with the use of time. The refractive index of the glass also changes greatly, which seriously reduces the imaging quality of the glass and affects the resolution of the system.

It is often necessary to use thermal aberration compensation technology to make up for it. For example, the lithography objective lens of a lithography machine is compensated by combining movable lenses and thermal aberration compensation components. However, these technologies have a high threshold and are only mastered by a few manufacturers in the world, which greatly restricts them. It hinders the promotion and application of related technologies, and it is not conducive to the formation of market competition and breaking the situation of expensive precision instruments

[0005] Moreover, the crystallization upper limit temperature of the existing heavy lanthanum flint glass is relatively high, the stability of the glass is poor during high temperature processing, and the thermal processing technology is difficult, so its application range is restricted. limit

[0006] In addition, the current high-density and high-coloring heavy lanthanum flint glass can not meet the requirements of people's pursuit of light and small instruments and equipment and high transmittance

Images