Multi-layer stacked narrowband color filter with high color purity and wide color gamut

Based on the MIMIM structure filter framework, this paper developed a multilayer filter termed multilayer stacked filter with alternating materials (MSFAs). The transmission wavelength can be dynamically tuned by adjusting the thickness of the magnesium fluoride (MgF₂) dielectric layer. Through the synergistic mechanism of localized surface plasmon resonance (LSPR) and Fabry-Pérot (F-P) interference, the present study is devoted to the realization of the multiband continuous color filtering function of the structure in the sensitive visible region of the human eye at 450-650 nm. The structure acts as a color bandpass filter with a maximum transmittance of 85.5% and a full width at half maxima (FWHM) of less than 9.5 nm. This plasmonic architecture facilitates wide-gamut RGB color space engineering, achieving spectral localization of primary colors at 59 nm for blue, 113 nm for green, and 185 nm for red via precise control of MgF₂ interlayer thickness. The filter can cover 163.4% of the sRGB standard color gamut and 121.2% of the Adobe RGB standard color gamut in the visible spectral range with a color purity of 97.3%. The MSFAs are designed to be simple, lithography-free, and highly integrated, offering a wide color gamut and high color purity, which provides innovative solutions for displays and imaging systems.