Germanium substrate 8-12 [mu] m infrared band diaphragm and preparation method thereof

Abstract

The invention relates to a germanium substrate 8-12 [mu] m infrared band diaphragm and a preparation method thereof, and belongs to the field of infrared optics. The diaphragm takes single crystal germanium as a substrate, and the front and back surfaces of the substrate are plated with the same infrared antireflection film system structures; and the structures of the infrared antireflection film systems on the front surface and the back surface are as follows: a substrate / 0.281 Ge / 0.475 ZnSe / 0.4641 Ge / 0.644 ZnSe / 0.578 YbF3 / 0.126 ZnS / air. According to the principle of destructive interference and constructive interference of light, the constructive interference of light can be maximized by using a multi-layer film structure, so that the transmittance of the coated lens is maximized. In the aspect of transmittance, due to the fact that Ge, YbF3, ZnS and other coating materials have absorption in the light-transmitting wave band, and meanwhile, tensile pressure stress between the film layers also absorbs light in the wave band, the thickness of the film layers with absorption is reduced to the minimum, and meanwhile, ZnSe materials with more perfect light-transmitting performance are adopted in the second coating film and the fourth coating film, so that the transmittance is improved, and the light-transmitting effect is improved. And in the film plating process, the film layer stress is reduced by adopting the modes of ion source assistant plating and bombardment before and after ion source plating, so that the film layer strength is enhanced while the absorption is reduced, and the transmittance is improved.

Description

technical field [0001] The invention belongs to the field of infrared optics, and in particular relates to a germanium-based 8-12um infrared band window and a preparation method thereof. Background technique [0002] Anti-reflection coating is also called anti-reflection coating. In optical components, light energy is lost due to the reflection on the surface of the component. transparent effect. The original anti-reflection coating is achieved by depositing a single layer of anti-reflection film material on the surface of the component, which can only anti-reflection for a single specific wavelength of electromagnetic waves. In order to achieve anti-reflection in a wider range and more wavelengths, it can be achieved by depositing multi-layer films. With the research experience on anti-reflection coatings, more materials that can be used as anti-reflection coatings have been discovered. At the same time, due to the development of coating technology, the application of ant...

AI Technical Summary

Problems solved by technology

For this reason, higher requirements are put forward for the infrared light transmittance and film firmness of germanium windows, while the optical film transmittance and film firmness of germanium windows produced by the existing production process are low, Unable to meet the requirements of military equipment

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