Design Of Super Absorption Structure And Its Sensing Application Based On Metasurface

The Surface Plasmon Polaritons(SPPs)in metal nanostructures can be applied into the new generation of ultra-sensitive detection and photon communication and computing chips due to their great enhancement of local electromagnetic field and their properties of propagation beyond diffraction limitation.With the development of nano-photonics,traditional materials can no longer meet the needs of micro-nano optics.The development of micro-nano fabrication technology provides technical supports for the design and manufacture of meta materials with exotic optical properties.Metamaterials are artificially designed materials arranged in periodic subwavelength arrays.Metasurfaces are two dimensional metamaterials with subwavelength thickness.The manipulation of space beam by metasurface has made great progress in recent years.Moreover,metasurfaces also have great potential in the utilization of super-absorbent light energy and ultra-sensitive sensing.However,due to the needs for sophisticated design and micro-nano processing technology,which leads to a large increase in costs,easier and cheaper ways of producing practical metasurfaces are needed.Therefore,this paper is mainly aimed at the numerical simulation design of super absorption and sensing metasurfaces,which is easy to be lowering the cost,and has good performances.At present,the super absorption metasurfaces have the shortcomings of too complex geometry and high fabrication cost.At the same time,most of the current researches focus on the infrared part of the spectrum,so the research on visible and near-infrared super absorption materials needs to be further studied.Therefore,this paper designs a super absorption metasurface based on the random distribution of gold particles adsorbed on ordered gold poles grown on anodic aluminum oxide template.The design principle of this metasurface can be obtained by simple chemical deposition method,which has the possibility of industrial popularization.For this reason,we used finite element method to analyze its optical properties,and found that its average absorption rate in the field of visible light can reach 94.5%.The current plasmon sensors are basically based on SPPs and Localized Surface Plasmon Resonance(LSPR).However,there are some drawbacks in the sensor design based on these two principles.The sensors based on SPPs need accurate incident Angle and a large number of optical components to be used at the same time.The sensitivity and quality factor(Q factor)of the sensor designed based on LSPR are not high enough due to the wide resonance line width.In order to solve these two problems,a novel refractive index sensor with high sensitivity and quality factor is proposed based on the interaction between LSPR and grating diffraction mode in this paper.In this paper,a super-narrow reflection peak based on the interaction between grating diffraction mode and LSPR is designed by using the nanoparticle/spacer/reflector structure to achieve high sensitivity sensing,and the sensing's FOM reaches 625.During the nanoparticle/spacer/reflector structure designing process,a new ring resonance gap mode caused by the strong coupling of the nanoparticle/spacer/reflector structure is analyzed with plasmon hybridization theory.The results of this paper will probably be an important reference for the construction of super absorption metasurface and plasmon sensing based on metasurface.