Design Of Wide Color Gamut Color Filter Based On Surface Plasmon Resonance And Optical Crosstalk Analysis Of CIS Pixel Array

Color filter is a commonly optical device,which is often used to transmit or reflect light of specific wavelength to display the desired color.Color filters are widely used in displays,image sensors,anti-counterfeiting technology,color decoration,color printing and other fields.The traditional color filters are made based on chemical dyeing.Pigments or dyes have different absorption characteristics for light in different bands.This feature is used to realize filtering.Although this kind of color filter has a low production cost,its chemical properties are unstable,and the life span is short.Therefore,a new kind of color filter is needed to replace the chemical color filter.The nanostructured plasma color filters have the advantages of stable color,small size,and good color reproducibility,and are expected to become an alternative to the existing chemical color filter.However,the color gamut generated by the existing plasma color filters is relatively narrow and cannot exceed the s RGB color space.The limited color gamut and low saturation limit the further application of plasma color filters.In order to overcome this shortcoming,a new structure of wide color gamut plasma color filter is proposed,and its structural characteristics are analyzed in detail.The main research contributions are as follows:(1)A wide gamut color filter based on surface plasmon resonance is designed.The nano pattern structure is etched on the surface of the silver film which is composed of cross holes and four rectangular arms.By changing the length of its rectangular arms,silver film thickness and structural period,the resonance wavelength of the plasma can be adjusted to obtain transmission spectra with different peak wavelengths.A wider color gamut can be obtained by plotting the calculated color coordinates of the transmission spectrum on the CIE1931 chromaticity diagram.The experimental results show that the peak transmittance of three primary colors of RGB can reach 50%,54% and 47%respectively,and the color gamut range and saturation can exceed the s RGB color space.The influence of structural parameters on the peak wavelength is analyzed qualitatively in theory,and the influence of structural parameters on the peak wavelength is explained from the distribution of surface electromagnetic field and longitudinal electromagnetic field.Finally,the structure of the color filters is optimized to reduce the sensitivity of the color filters to the incident angle.(2)The spatial optical crosstalk model of wide color gamut color filter based on surface plasmon resonance is established.When the structured color filter and the chemical color filter are integrated into the CMOS image sensor pixel,the spatial optical crosstalk between adjacent pixels is quantitatively calculated when the height of the color filter from the photosensitive area at the bottom of the image sensor pixel and the angle of incident light are different.The data obtained are analyzed,and the effects of different factors on the crosstalk are analyzed from the perspective of electric field.It can be found that when the incident light angle is constant,the smaller the distance from the color filter to the photosensitive area at the bottom of the CMOS image sensor pixel,the smaller the crosstalk value generated.With the increase of the incident light angle,the crosstalk value will also increase.Using this conclusion to optimize the pixel structure of CMOS image sensor can greatly improve the imaging quality of image sensor.