Ultrawide-angle hemispherical lens antireflection film and coating method thereof

Abstract

The invention relates to an ultrawide-angle hemispherical lens antireflection film and a coating method thereof. The spectral range of the antireflection film is broadened from the perspective of the design of the film system by changing the conventional design thought so that the thin position of the edge film layer is enabled to still achieve the antireflection effect. The film thickness within the same circumference of a lens is ensured to be uniform only by controlling the deposition rate of the film material layer and the revolution speed of a workpiece disc without modifying conventional equipment. The adhesion and the compactness of the film layer are enhanced by adopting the film coating technology of ion source etching and ion source auxiliary deposition. According to the design, the film layer close to a substrate uses TiO2 and SiO2 and the ion source is additionally arranged for assistance so that the stress problem of the TiO2 and MgF2 film layers can be effectively solved and the risk of film cracking can be eliminated; and the outermost layer uses low-refractivity MgF2 so that the reflectivity of the whole bandwidth can be reduced to the largest extent, the bandwidth can be broadened and the low reflectivity can be guaranteed, and the film layer stress can be reduced and the risk of film cracking can be reduced.

Description

Technical field [0001] The invention relates to an anti-reflection coating of an ultra-wide-angle hemispherical lens and a coating method thereof, in particular to a lens anti-reflection coating with a curvature equivalent to the aperture and a coating method thereof. Background technique [0002] Optical film is an indispensable device in modern optical systems, and plays a pivotal role in optical instruments. With the development of optical products, the application of optical lenses is becoming wider and wider. For high-definition, wide-angle, and starlight lenses, they are all moving in the direction of large numerical aperture and large light flux, so the coating of the lens is very important. During the coating process, the film thickness of each point on the same lens surface has a certain difference due to the different vapor deposition angles of the film material generated by the point source, which has no obvious effect on the lens with smaller curvature, but for the l...

AI Technical Summary

Problems solved by technology

[0004] The invention provides an anti-reflection coating for an ultra-wide-angle hemispherical lens and a coating method thereof. The invention selects SiO 2 、TiO 2 , and MgF 2 As a coating material, an anti-reflection film is coated on the lens body, which solves the problem that the anti-reflection film cannot play an anti-reflection role due to the uneven thickness of the center and edge of the lens.

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