Research On Sub-wavelength Structure For Continuously Adjustable Color

Compared with the color formed by the absorption of traditional chemical dyes,the color formed based on the modulation of the electromagnetic field of incident light by the structure at the sub-wavelength size has the advantages of stable color,wide color gamut,and no environmental pollution,there is a broad potential application market in the industrial field.This structural color,which depends on the structure of matter,is rooted in various mechanisms of light and matter interaction,such as interference and light field scattering.This thesis mainly studies the light-field regulation mechanisms of metal-dielectric-metal structures and nanoparticle arrays,and analyzes the formation,optimization and adjustment of structural color,and the preparation of structural color devices.The research content is as follows:1?The structure color realization and control mechanism based on Au-Zn O-Al devices were studied,and the light field control characteristics of the device were simulated using FDTD software.The relationship between the perfect absorption characteristics of the device wavelength selection and the resonance absorption of the Fabry-Perot microcavity,the polarization independence of the device's control of the incident light field,and the angle dependence of the incident light were discussed.The role of the top metal layer and the intermediate dielectric layer in obtaining a wavelength-selective perfect absorber with a high quality factor was studied,and the direction of improving the metal-dielectric-metal structure quality factor was pointed out.Based on this,Ti N-based alternative devices have been developed,the device structure with continuously adjustable colors in the visible light range was realized through simulation,and the device with continuously changing colors was prepared according to the simulation results.The effects of changes in parameters such as the array period P,the cross-sectional area S of the upper surface of a single prism,and the thickness of the three-layer film on the reflection peaks were studied.2?A triangular prism array structure of Ti N-Si3N4-Si is proposed,which is simulated using FDTD software,and the reflection spectrum is continuously adjustable in the visible range by adjusting the structural parameters.The resonance mode based on the coupling of Mie scattering and the F-P cavity realizes a single-peak scattering spectrum with continuously adjustable resonance wavelength in the visible light range.The resonance peak with high quality factor is optimized to obtain a structural color with higher saturation.The relationship between the polarization characteristics of the incident light and the resonance wavelength is further explored,the research shows that the structure color based on the nanoparticle array has polarization correlation.