| Metasurface is a kind of two-dimensional metamaterial,which not only has the advantages of three-dimensional metamaterial,but also has the advantages of low profile and low loss,which has great application value in filters,new antennas,absorbers and biosensors.However,traditional supersurface absorbers have two defects.One is that the absorption peak bandwidth is wide and the quality factor Q is low,which affects the detection sensitivity and sensing performance of the absorbers.The other is that the traditional metal-based absorber can only be realized at a fixed absorption frequency,and the absorption peaks of other frequencies can only be adjusted by re-optimizing the geometric parameters.Recently,the body of the Dirac semimetal(BDS)caused the researchers of great interest,BDS is a new type of material,also known as the "three-dimensional graphene",it not only has a very high carrier mobility at the same time also has the characteristics of adjustable dielectric constant in a perfect absorber,biological sensors and environment detection has potential application prospect.In this paper,BDS is used as the main material to study the optical properties of grooved grating absorber and circular porosity detector based on BDS.This device is very sensitive to the change of background refractive index.Based on the adjustable characteristics of Volume Dirac semi-metal,it can dynamically adjust the absorption frequency without re-optimizing geometric parameters.At the same time,it can still maintain perfect absorption under the condition of constant scale change of structure.The main work of this paper is as follows:(1)The longitudinal dynamic conductivity of BDS is calculated by the random phase approximation method,and the equivalent permittivity of BDS is obtained according to the two-band model.The theoretical investigation on the dispersion relationship shows that BDS gratings can be regarded as one-dimensional photonic crystals.At the same time,the theory of supersurface perfect absorption and BDS adjustable performance is investigated and analyzed to pave the way for further exploration of BDS supersurface perfect absorption.(2)A kind of high quality factor perfect absorber with tunable and sensing based on BDS is studied.Under the premise of applying BDS,the supersurface perfect absorber is matched with appropriate structural parameters by dichotomy calculation and dispersion curve study.The perfect absorption characteristics are completed by time coupling mode and numerical simulation calculation,and the analysis of field distribution and the strong proof of far-field incidence are realized.Secondly,it realizes the characteristics of hypersurface regulation under the premise of BDS application,analyzes its geometric variability and sensing characteristics,and completes the research on its sensing characteristics.(3)studied a short channel detector of the optical properties based on the BDS,using the BDS and metal electrode structure with a vertical structure of asymmetric short channel device,through the design of the surface structure of BDS cycle,short channel effect combined with perfect surface plasma resonance absorption characteristics,the parameters of the structure was optimized by dichotomy,The perfect absorption simulation of the structure is completed,and other optical properties of the structure are further studied.The overall simulation results have a certain application prospect for the subsequent experimental work. |
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