Optimization Design And Absorption Characteristics Analysis Of Composite Structure Anoantenna

Nanoantenna is a kind of photon device which can control light wave at nanometer scale.In this paper,we mainly study the design of optical nanoantenna structure.The main principle is to control the resonance distribution of surface plasmon by changing the appearance,size,dielectric material and other factors of the nanoantenna within the sub wavelength size.The model simulation and absorption calculation analysis of nanoantenna composite structure are involved.The numerical method mainly uses the combination of FDTD and optimization algorithm,and uses the numerical analysis software and algorithm to build the model and simulate the calculation.The main work of this paper is as follows:First of all,the design and analysis principle of nanoantenna structure is described in theory,the structural characteristics of multi slot and butterfly dipole are analyzed,and the multi slot butterfly dipole composite structure antenna model is established in the experiment.The optical response of the optical nanoantenna under the condition of single structure and composite structure is analyzed.The experimental results show that the composite structure nanoantenna has good absorption characteristics,and its average absorption rate is 84.1% in the band of 400-1800 nm.In addition,the absorption characteristics of the array are analyzed under different materials,sizes and polarization angles.Secondly,on the basis of the above work,an intelligent optimization algorithm is proposed to optimize the structure parameters of nanoantenna,and the double butterfly double ring groove composite structure nanoantenna is designed with the help of genetic algorithm.In the experiment,the absorption function is used to control the evolution direction of the population,and the genetic operator is used to select the antenna structure parameters that meet the requirements.The experimental results show that the optimized antenna structure has good absorption characteristics,and the average absorption rate in the range of 400-1800 nm reaches 78%.In addition,the structure has good polarization insensitivity.Finally,because the traditional design method of nanoantenna is based on the physical experience formula,the process needs to be expensive.In this paper,a new method of inverse design of nanoantenna structure using artificial neural network algorithm is proposed,and a cylindrical nanoantenna with high absorption performance is designed.The experimental results show that the artificial neural network has a good fitting property for the relationship between the cylindrical nanostructure parameters and the absorption spectrum,and the average absorption rate of the cylindrical antenna in the 400-2000 nm band is as high as 89%.To sum up,this paper proposes the nanoantenna structure by different design methods.At the same time,the theoretical analysis and experimental verification of various nanostructure design methods are carried out,and the absorption characteristics of nanoantenna structure are analyzed.This is of theoretical significance to the structural design of optical nanoantenna and the development of optical devices.