A kind of sapphire optical window with electromagnetic shielding function and its preparation method

Abstract

The invention discloses a sapphire optical window with an electromagnetic shielding function. The sapphire optical window comprises a sapphire substrate; an electromagnetic shielding functional film layer, a hard multiband antireflection film and a hydrophobic film which are sequentially evaporated on the sapphire substrate. The electromagnetic shielding functional film layer is composed of a first aluminum oxide film layer, a metal mesh film layer embedded into the first aluminum oxide film layer and a second aluminum oxide film layer plated on the metal mesh film layer. The metal mesh film layer is formed by the periodic arrangement of square mesh units in a first aluminum oxide film layer, and the edge of the second electromagnetic shielding functional film layer is plated with an edgeelectrode film layer forming ohmic contact with the metal mesh. The invention also discloses a preparation method thereof. According to the invention, the sapphire optical window is mainly used in a marine environment and an underwater pressure-bearing environment, and the window has the functions of 4MPa water pressure resistance, salt mist resistance, seawater soaking resistance and mould resistance, and has high transmittance in visible light and medium-wave infrared bands, wherein the average electromagnetic shielding effectiveness at 30MHz-1.5 GHz bands reaches 30dB or above.

Description

technical field [0001] The invention belongs to the technical field of optical thin films and micro-optical processing, and in particular relates to an optical window embedded in a sapphire substrate with an electromagnetic shielding metal grid and a preparation method thereof. Background technique [0002] With the development of science and technology, the space electromagnetic environment is becoming more and more complex. There are serious electromagnetic interference problems in the photoelectric windows in the fields of remote measurement and remote sensing, medical diagnosis, secure communication, sea, land and air equipment. Internal working devices are interfering. [0003] In the military field, on the one hand, the enemy's electromagnetic interference equipment and our high-power transmitting equipment will have a serious impact on the normal operation of the photoelectric equipment; on the other hand, the electromagnetic waves leaked through the optical window wi...

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Problems solved by technology

[0012] The above patents have a common shortcoming, that is, the protective structure of the grid is too simple, and the electromagnetic shielding light window produced can only be used in land and aerospace environments where the use environment is not harsh, and cannot be used to resist salt spray, heat and humidity, and mold. Marine environment with requirements and underwater environment with pressure resistance requirements for windows

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