Wide-angle-incidence infrared cutoff optical filter without half-wave hole and membrane system design method thereof

Abstract

The invention relates to a wide-angle-incidence infrared cutoff optical filter without a half-wave hole and a membrane system design method thereof. The wide-angle-incidence infrared cutoff optical filter comprises a substrate, a first membrane stack, a second membrane stack and a third membrane stack, the first membrane stack is deposited on the upper surface of the substrate, the second membranestack is arranged on the upper surface of the first membrane stack, the third membrane stack is arranged on the upper surface of the second membrane stack, the shapes of optical thickness coefficientcurves of high-refractive-index material membrane layers and low-refractive-index material membrane layers of the same membrane stack of the first membrane stack and the second membrane stack are thesame, and the curve shapes are 0-pi sinusoidal waveform or pi-2pi sinusoidal waveform. According to the infrared cutoff optical filter obtained by preparation, when the incident angle is 0-40 degrees, the transmittance of a visible wavelength region is not locally decreased, the half-wave hole is avoided, the average transmittance of the 400-650 nm waveband is greater than 94%, the balance of colors of lights through the infrared cutoff optical filter is guaranteed, and the imaging colors are real.

Description

technical field [0001] The invention relates to a large-angle incident infrared cut-off filter without a half-wave hole and a film system design method thereof, belonging to the technical field of optical thin films. Background technique [0002] In the mobile phone camera, the infrared cut filter located in front of the image sensor CCD or CMOS can effectively filter the infrared light and pass through the visible light, thereby producing a normal color image, which is a key component in the camera. With the continuous improvement of mobile phone pixels, higher and higher requirements are put forward for infrared cut filters in terms of clear imaging, true color reproduction, blue light compensation, and reduction of inter-mirror reflection. The geometric size of the filter itself is relatively small, and the geometric size of the subject is much larger than the geometric size of the lens, so that a large part of the reflected light from the subject will enter the lens at a...

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Problems solved by technology

[0005] The purpose of the present invention is to solve the problems of partial drop in transmittance in the visible wavelength region and the appearance of half-wave holes when the large angle AOI=0~40° is incident, and to provide a kind of filter that can effectively suppress light relative to the infrared cut-off filter. Infrared cut-off filter and its film system design method affecting the camera image when the incident angle of the light sheet (AOI=0~40°) is large

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