Design of broadband achromatic polarization multiplexing super lens based on particle swarm optimization

The invention provides a broadband achromatic polarization multiplexing super lens design method based on a particle swarm algorithm. The super lens comprises a silicon dioxide substrate layer and a titanium dioxide super surface layer with anisotropy. A phase response database is constructed by scanning the size of a structural unit with an elliptical cross section, and different phase responses are obtained. In combination with an existing database, phase distribution of different wavelengths under x and y linear polarization channels is customized by using a particle swarm optimization (PSO) algorithm, so that the matching error is greatly reduced. Finally, simulation proves that the focal length of the super lens can be adjusted according to the polarization state of incident light, and dispersion under dual polarization can be effectively controlled. The design has the advantages of compactness, flexibility, high efficiency and the like, and has wide application potential in the fields of medical imaging