Wide Color Gamut and Multi-Band Color Filtration With MIM Structure Plasmonic Filters

Color filters are extensively utilized in various applications, including photovoltaic devices, printing, liquid crystal displays, image sensors, digital photography, projection systems, and other optical instruments. In this paper, an F-P cavity structure based on an metal-insulator-metal (Ag-ZnS-Ag) structure is designed. By selecting specific materials and tuning structural parameters, strong coupling effects are formed through the interaction between the Fabry-Pérot (FP) resonance in the intermediate dielectric cavity and the LSP resonance on the metal surface. This structure can generate a narrow-band resonance peak within the visible light spectrum. By tuning the thickness of the dielectric cavity, color filtration across the 380–700 nm range can be dynamically obtained, enabling continuous multi-band filtering within visible light. Within the visible light range, this structure, functioning as a filter, can achieve a transmission efficiency of up to 56% and a FWHM of 10–24 nm. Additionally, this structure can be used to design wide-color gamut plasma filters for constructing RGB color spaces. When the ZnS thickness is 55 nm, it corresponds to the blue channel of the color space; at 75 nm, it corresponds to the green channel; and at 95 nm, it corresponds to the red channel. This color space can cover 100% of the sRGB color gamut and 99.946% of the Adobe RGB color gamut. In summary, this structure provides a new approach for designing simple, photolithography-free plasma filters that enable multi-band color filtration and exhibit a wide color gamut.