Double band-pass cut-off composite filter film, filter and preparation method thereof

Abstract

The invention provides a double-bandpass cut-off type filtering film. A film system structure is (LH)S, wherein L represents silicon dioxide film layers, H represents trititanium pentoxide film layers, S is a periodic number, and a value range is 21 to 23; a film layer adjacent to a substrate is a first layer; the trititanium pentoxide film layers are adopted, and the geometrical thicknesses of the trititanium pentoxide film layers are 177 to 178nm; an outermost layer is an S layer and adopts the silicon dioxide film layer with the geometrical thickness of 178 to 179nm; in the second layer to the S layer, even number layers are all silicon dioxide film layers, and the geometrical thicknesses of the even number layers are 50 to 101nm; odd number layers are all trititanium pentoxide film layers with the geometrical thicknesses of 30 to 50nm. The invention also provides an optical filter with the filtering film and the preparation method of the optical filter. According to the double-bandpass cut-off type filtering film, the optical filter and the preparation method of the optical filter, provided by the invention, the interference of an aircraft cockpit on external observation of night vision goggles can be avoided; meanwhile, naked eye observation for instruments inside the cockpit is not affected, and the night observation capability of aviators is improved.

Description

technical field [0001] The invention relates to the technical field of optical films, in particular to a double-band-pass cut-off composite filter film, a filter and a preparation method thereof. Background technique [0002] When flying at night, pilots need to wear night vision goggles in order to protect their vision from the cockpit lighting and instruments in the cockpit. Class C NVIS (Night Vision System) dual-band-pass cut-off composite filter film can realize the lighting of the aircraft cockpit without interfering with the pilot's external observation, and at the same time does not affect his naked-eye observation of the instruments in the cockpit, achieving night vision compatibility. Therefore, this type of night vision goggles can be used for night vision compatible modification of active aircraft, or configured for pilots to improve the pilot's control level of aircraft at night. However, the complex film structure of the existing C-type NVI S dual-bandpass cut...

AI Technical Summary

Problems solved by technology

However, the complex film structure of the existing C-type NVI S dual-bandpass cut-off composite filter film leads to difficulties in its preparation process, making the function of the filter film made unstable.

It can be seen that the existing dual-bandpass cut-off composite filter has the problems of unreasonable film structure and difficult preparation

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