Novel cloaking devices for surface wave and thermal manipulation : from theory to implementation

Abstract

The thesis studies the practical realization of manipulation of electromagnetic energy based on the area-preserved affine transformation optics method, and further investigates the manipulation of thermal energy with the design of a three-dimensional thermal cloak. Electromagnetic Manipulation based on Transformation Optics method enables unprecedented waveguiding concept and devices, with the representative example of invisibility cloaking and waveguiding device, and their realizations in two-dimensional scale. Although functionalities of various cloaking and waveguiding designs are ideal in theory, their experimental realizations remain imperfect due to the limitation of complex electromagnetic constitutive parameters. We overcome the problem of complex requirement of constitutive parameters in electromagnetic transformation-based devices by re-designing the coordinate transformation process. The solution is the area-preserved affine transformation method, in which the transformation process is linear, and the area is preserved during transformation. The solution reduces requirement of constitutive parameters from inhomogeneous permittivity and none-unitary permeability to homogeneous permittivity and unitary permeability, without compromising device functionalities. We demonstrate the effectiveness of method through the theoretical design and experimental realization of surface wave manipulation devices. We further extend the study of manipulation of electromagnetic wave to manipulation of conductive heat flux, which in macroscopic scale is in analog to zero-frequency electromagnetic phenomena such as direct current and static magnetic field. We introduce the design, fabrication and characterization of the first three-dimensional thermal invisibility cloak.