Fluorophosphate glass, glass preform, optical element, and optical instrument provided with optical element

Abstract

The invention discloses a fluorophosphate glass, a glass preform, an optical element, and an optical instrument provided with the optical element. The fluorophosphate glass comprises cations and anions, and the cations comprise 25-40 mol% of P<5+>, 8-22 mol% of Al<3+>, 0-8 mol% of La<3+>, 1-10 mol% of Y<3+>, 3-15 mol% of Sr<2+>, 25-40 mol% of Ba<2+> and 1-10 mol% of Gd<3+>; and the anions comprise38-50 mol% of F<-> and 50-62 mol% of O<2->, wherein a ratio of n(Y<3+> + La<3+>) / n(P<5+> + Al<3+> + Sr<2+> + Y<3+>) is more than 0.07. The fluorophosphate glass has a refractive index of 1.52-1.60 and an Abbe number of 68 or more, and has excellent optical properties and a low refractive index high temperature coefficient, so the fluorophosphate glass has an excellent thermal stability under strong light, and the stress is not prone to be generated in the glass, thereby the quality of the imaged image is improved, and the needs of the market are met.

Description

technical field [0001] The invention belongs to the technical field of fluorophosphate glass, in particular, the invention relates to fluorophosphate glass, a glass preform, an optical element and an optical instrument having the same. Background technique [0002] Fluorophosphate optical glass is a special optical glass with low dispersion, which can eliminate secondary spectral chromatic aberration, improve the imaging quality of optical lenses, and has a low softening point, and can be made into aspheric lenses by one or two pressings , is an excellent optical material for the production of advanced digital products. [0003] At present, most fluorophosphate glasses have a large stress optical coefficient, and the thermal stability of the glass is not good under strong light, and the temperature rises rapidly, and stress is easily generated inside the glass, thereby reducing the imaging quality or even no imaging, so the refractive index nd is 1.52 High refraction low di...

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Problems solved by technology

[0003] At present, most fluorophosphate glasses have a large stress optical coefficient. The thermal stability of the glass is not good under strong light, and the temperature rises rapidly. Stress is easily generated inside the glass, thereby reducing the imaging quality or even no imaging. Therefore, the refractive index nd is 1.52. ~1.60, Abbe number vd not less than 68, and high refraction and low dispersion colorless fluorophosphate glass with small stress optical coefficient, the market demand is urgent

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