Research On The Design Method Of Devices Based On Metasurface

Metasurface is a new type of artificial two-wavelength electromagnetic material.By adjusting the parameters,geometry and arrangement of the dielectric structure on its surface,it can flexibly regulate the amplitude,phase and polarization of the spatial scattering field,thus realizing a variety of optical functions.Of traditional surface design method by theoretical analysis to optical phase amplitude control,this method needs to have a large number of optical knowledge and design experience,design is difficult,and design results accord with theoretical expectations,not in order to solve this problem,this paper has carried out over the surface of the inverse design method research,combined with the actual application,design a variety of functions of super surface lens,and on the basis of this design method,studied the super surface in the form of nerve,the paper research content includes:1.Research on the inverse design method of metasurface lens.First,the two-dimensional metasurface design method is studied.The scattering field of the non-periodic metasurface is calculated by solving the scattering field of the periodic metasurface structure.On this basis,the metasurface cell structure is constructed as the parameter,the metasurface The scattering field distribution is an objective function optimization problem.The corresponding optimization algorithms are selected for single-function and multi-function targets.Three single-wavelength focusing lenses are designed.The focusing efficiency at 480nm,530nm,and 650nm is 85.%,91%,81%,a multi-wavelength focusing lens,focusing efficiency of 53%,80%and 55%at 480nm,530nm,650nm,a multi-wavelength beam splitting focusing lens,at 480nm,530nm,650nm The focusing efficiency reaches 36%,34%,and 38%.Subsequently,the design of the cell structure of the three-dimensional metasurface was discussed,and a three-dimensional multi-wavelength focusing lens was designed based on the design method of the two-dimensional metasurface,and simulation verification was carried out.The best results are at 480nm,530nm,and 650nm,the focusing efficiency reaches 51%,48%,42%.2.Research on the design of neuromorphic supersurface.Based on the inverse design method of the metasurface lens,the incident light propagating through the multilayer metasurface structure is analogous to the forward propagation of the neural network,a model of the forward propagation of the metasurface light field is built,and the loss is defined according to the field distribution of the output layer Function,the optimization problem of neuromorphic hypersurface design is established.The handwriting data set(MNIST)was used as input data to train it,and the recognition of handwriting data set was completed.The training and recognition results of different network structures were discussed.The accuracy of two-dimensional neuromorphic hypersurface recognition can reach 83%.The accuracy of 3D neuromorphic hypersurface recognition can reach 85%.