Design Of Invisibility Device Based On Conformal Transformation Optics

Compared with the traditional geometric optics theory,transform optics provides a simpler method for calculating the distribution of spatial material parameters.Because the selection of the transformation function has a certain degree of flexibility,people can design devices that work in various frequency bands according to actual needs,such as waveguide bends,antennas,wave absorbers,and invisibility cloaks.This thesis mainly starts with conformal transformation optics,studies its application in stealth devices,and discusses the material parameters of the devices.The main work of this thesis is:1.A conformal invisibility carpet is designed by using the Zhukowski transformation.The carpet has an isotropic material parameter distribution and achieves perfect invisibility at any angle.In addition,in order to optimize the refractive index distribution of the above-mentioned carpet,this thesis also uses two symmetrical Maxwell's fish eye lenses to improve the carpet structure,and its maximum refractive index is reduced from 32.9 to 8.5.2.This thesis proposes a new conformal transformation based on the Zhukowski transformation,that is,the linear-hyperbolic sine transformation.Secondly,by analyzing the transformation,a conformal cloak is designed.The cloak uses isotropic material and achieves perfect invisibility.Then the electric field distribution of the line current source in the invisibility cloak is discussed,and more application scenarios of the invisibility cloak are explored.Finally,based on the linear-hyperbolic sine transformation,a perfect invisibility carpet is designed.The carpet does not have refractive index singularities,and a compromise can be made between cloak area and refractive index distribution according to actual needs.This thesis mainly uses conformal transformation optics to calculate the invisibility area and refractive index distribution of the device,and uses ray tracing and full-wave simulation to verify the stealth performance of the device,and then demonstrates the feasibility of the stealth device under geometric optics and wave optics.It can be seen that transformation optics has good application potential and development prospects.