Design,Fabrication And Performance Of Surface Plasmon Structural Color And Metasurface Absorber

Surface Plasmons(SPs)are the collective oscillations of free electrons on metal surfaces under the excitation of external electromagnetic fields.SPs can control the incident light in micro-nano structures due to its optical properties of local field enhancement and subwavelength propagation.With the support of the modern preparation technology of micro-nano structure,combine surface plasmon photonics with metasurface,we can study the mechanisms of the interaction between light and matter(or structure)at the subwavelength scale.And we can effectively achieve narrowband absorber,broadband absorber,structural color device,etc.These have potential applications in the optical camouflage,ultra-black stealth,infrared stealth and so on.This topic focuses on the application prospect of surface plasmon metasurface in structural color and optical broadband absorber,aiming to design the metasurface structure to meet the performance requirements by a simple and effective method.Which are used to achieve the metasurface structural color and perfect broadband absorber.Based on the different loss characteristics of SPs excited by incident light in metasurfaces composed of different materials and patterns,the design and preparation of narrowband and broadband metasurface absorber have been carried out.The main research contents and achievements are as follows:(1)Using the traditional metal-dielectric-metal(MDM)metamaterial structure,a dual narrowband absorber located in the near-infrared was designed.The absorber consists of a bottom Au mirror,middle dielectric layer and upper Au cross nanostructure.The absorber achieved two narrowband absorption peaks around 850nm and 1600nm,respectively.In addition,the structural evolution of the MDM absorber shows that the simplified all-metal metasurface structure and the dielectric metasurface structure can achieve narrowband absorption at similar short wavelength.Because the absorption of all-metal and dielectric metasurface absorbers at specific wavelength is equivalent to that of MDM metamaterial absorber based on the common effect of surface lattice resonance,which provides theoretical support and design basis for achieving narrowband and broadband absorbers in subsequent studies.(2)A dielectric nanoring-metal(Al)structural metasurface absorber was proposed.The results of parameter analysis show that the peak position,bandwidth and intensity of the absorption peak are related to the refractive index and structural parameters of the nanoring.When the dielectric material of nanoring is Al₂O₃,the absorber can achieve dual narrowband absorption performance at 401nm and 566nm.,respectively.The corresponding full width at half maximum(FWHM)of the two peaks are 4.6nm and 29.1nm,respectively.The absorption intensity of the two peaks are 96.72%and99.75%,respectively.In addition,the simulation result when the Al film is oxidized shows that the structure has good stability.This lays a foundation for using dielectric-metal metasurface to achieve stable and effective structural color.(3)Based on the results of the study on the dielectric-metal structure,a TiO₂metasurface structure was designed to realize the structural color.The structure is composed of a two-dimensional periodic TiO₂ nanodisk array and a metal Al film.The structural color properties are studied by numerical simulation and experimental preparation.The numerical simulation results show that the metasurface can achieve different reflection curves under different structural parameters,and then display different structural colors.That is,the structural color has parameter adjustability.The test results of the experimental samples show that the prepared metasurface has good integrity,and the variation rule of the measured microspectral curves is basically consistent with the simulation results.In addition,the 2×2 array resolution of the structure is more than 25000dpi,and it has a good imaging effect.Therefore,the TiO₂ metasurface structural color device has a great application in optical camouflage,high resolution display,anti-counterfeiting printing and so on.(4)The performance of absorbers based on hexagonal array and tetragonal array were studied,and a broadband absorber based on high-loss metal nanoring array was proposed working in visible region.In the visible region,the average absorption of tetragonal lattice and hexagonal lattice absorbers are 97.6%and 96.2%,respectively.And the absorption intensity of the both peaks are more than 99%.The results of electric field and thermal field analysis show that the high and broadband absorption performance is due to the high localized surface plasmon resonance(LSPR)of the nanoring metasurface.In addition,the broadband absorber is polarization insensitivity,wide incident angle,parameter adjustability,etc.Therefore,it has candidate applications in ultra-black stealth,solar photovoltaic cells,heat radiators,photoelectric devices and so on.(5)Based on the research results of the visible light broadband absorber,a discrete square ring structure absorber based on high-loss metal titanium(Ti)working in the near infrared band was proposed.The simulation results show that the absorption of the absorber is more than 90%in the wavelength range of 895?2269nm under normal incidence.The analysis results of electric field and thermal field show that the high and broadband absorption are attributed to the local effect of strong electric field and the localized surface plasmon resonance effect with low Q value supported by the metal Ti.Combined with the research results of the electromagnetic parameters of different types of metal materials,the loss of incident light energy mainly comes from two parts:one is the intrinsic loss caused by the continuous electron transition excited by the incident light;the other is the resistance mainly depends on the enhanced localized electric field caused by the structure.In addition,the broadband absorber has the properties of polarization insensitivity,wide incident angle and high-loss metal selectivity.Therefore,it has potential application prospects in infrared stealth,thermal radiation measurement,energy collection and so on.