Study On Actively Tunable Filter Technology Of Nanostructure Based On Surface Plasmons

Filters are indispensable parts of modern micro-nano sensing technology.Traditional filter devices are mostly made of organic dyes,which are easy to decompose and fail in environments such as high temperature and ultraviolet irradiation for a long time,affecting the sensing performance of the filter.The surface plasmon filter can display different colors only by changing the size and geometry of the metal structure,which overcomes many shortcomings of traditional dye filters.However,the color range of the prepared material and the angle sensitivity of the nanostructure make the surface plasmon filter have low resonance intensity,narrow absorption band and are greatly affected by the incident light angle.Based on the analysis of the filtering characteristics of various special nanostructure filters,this paper combines metal nanostructures with liquid crystal materials to construct an active tunable filter device,and combines perovskite new materials to maximize the surface plasmon resonance response intensity and optimize the filtering effect.In this paper,a special structure grating array is prepared by combining the characteristics of hyperbolic photonic crystal polaritons,and the controllable propagation direction of light at a specific wavelength is realized.The main contents of the study are as follows:Aiming at the problem of narrow absorption band range of the filter,a transmission filter based on ultra-small spacing gold and silver nanorod arrays was prepared to achieve high-precision splitting in the visible light band.The air-filled and metal-filled coaxial nanoring filter structures were prepared,and the tunable characteristics of transmission resonance at visible light frequency were verified.Based on the wavelength selection characteristics of the optical response of the broadband light source through the nanoring,the absorption band range of the filter was broadened.Aiming at the problem of slow response speed of traditional filters,a reflective filter based on ultra-small spacing silver nanopillar array was prepared.By controlling the geometric shape of the array,the active adjustment of plasma resonance was realized,and a single color was further filtered from the broadband light source.On this basis,the prepared nanopillar array with spectral splitting effect and the liquid crystal doped with photoreactive azo dye are combined to realize the precise control of the medium environment in which the filter is located,and the surface plasmon resonance intensity and the response speed of the filter are improved.Aiming at the problem of low detection accuracy of the incident light of the filter that restricts the filtering effect,combined with the sensitive reaction characteristics of perovskite materials for optical detection,a high-performance MAPbI₃-Au hybrid photodetector was prepared by introducing a Au array into the methylammonium lead halide（MAPbI₃）system,which solved the problems of low light transmission and low detection reaction sensitivity of mixed light,maximized the surface plasmon resonance response,and further improved the purity of filtered monochromatic light.Aiming at the angle sensitivity of the incident light of the filter,an asymmetric photonic crystalα-MoO₃based on hyperbolic phonon polaritons is proposed.Based on its in-plane anisotropy,the controllability of light propagation in a specific direction is realized by exciting and regulating its low-symmetric deep sub-wavelength Bloch mode.The research content of this paper has potential application value in the fields of display and sensing,and provides new ideas and solutions for improving the performance of filters and expanding the application fields of filters.