Thermally Controlled Refractive Index And Nonreciprocal Goos-H(a|:)nchen Shift Based On Magnetic Metamaterials

Metamaterials are artificial materials with sub-wavelength structure. Whereas conventional materials derive their electromagnetic (EM) characteristics from the properties of atoms and molecules, metamaterials enable us to design sub-wavelength "atoms". Thus metamaterials access new functionalities which is hardly occur in the nature, such as EM invisibility, negative index material, zero-index material, break-ing the diffraction limit and achieving optical super resolution, and many other nonre-ciprocal properties. Metamaterials are not confined the exotic EM properties, and to realize a more flexible and feasible design, tunable metamaterials are also proposed. Because of the exotic properties and the tunable ability, metamaterials are wildly re-searched in the microwave, terahertz wave, infrared wave and visible light. The dis-sertation researches on the thermo-tunable metamaterials, zero-index metamaterials and the Goos-Hanchen shift effect in microwave. It is consisted of four chapters, the first chapter is the introduction of background and theory. Other three chapters are as follows:In chapter two, the tunable magnetic metamaterial with external magnetic field is already realized in the theory and experiment. Considering the influence of tempera-ture to the ferrite, we design a thermo-tunable magnetic metamaterial. Using the thermos-control instead of external magnetic field, the design will become more flex-ible.In chapter three, within the matched zero index magnetic metamaterial (ZIMM), EM wave can propagate without any phase delay, resulting in the manipulation of phase pattern in space. By simulating the electric field patterns of a Gaussian beam incident on ZIMM slabs with different thickness, zero phase delay inside the slab can be observed. By designing various outgoing interfaces a plane EM wavefront can be transformed into a cylindrical one, separated into two parts or even into a more gen-eral wavefront.In chapter four, around the working frequency of zero index the EM wave may not matched into the magnetic metamaterial, sometimes total internal reflection oc-curs. After optimizing we finally get the Goos-Hanchen shift around 1 to 2 wave-length in our system. And this phenomenon even happens in normal incidence. Con-sidering the normal incidence Goos-Hanchen shift is never happening in traditional optics because of the reversibility, then it exhibits the nonreciprocal properties in our metamaterials.