Wave Propagation And Optical Manipulation Of Metamaterials

In this thesis, we investigate the interation between electromagnetic waves andmetamaterials, such as nonlinear composites, anisotropic materials and gain media. We arefocus on the Goos–H nchen shift, Fano resonance, total transparency, ground cloak and soon. The main results are as follows.1. Goos–H nchen shift of the reflection from nonlinear nanocompositesBased on Maxwell-Garnett theory and effective medium approximation, we study twostructures of nonlinear nanocomposites. Firstly we derive the field-dependent effectivepermittivity of nonlinear composites. Then, the stationary phase method is adopted to studythe GH shifts from nonlinear composites. The shift is strongly dependent on the volumefraction, the shape of the metallic particles, and the incident angle. The reversal of the GHshift may be controlled by adjusting both the incident angle and the applied field. Thelateral shift is found to exhibit hysteretic effects including single optical bistability, doubleoptical bistability, and optical tristability. Numerical simulations based on Gaussian wavesare in good agreement with our theoretical calculations.2.Anisotropy-induced all-angle transparency through a metallic film andforce-loaded transformation devicesWe propose an anisotropic route to perfect electromagnetic (EM) wave tunnelingthrough a metallic film which relies on anisotropic coatings. EM transparency is achievedin such a anisotropic-metal-anisotropic structure for both polarizations and extremelynegative permittivity is not required in our method. The criterion for perfect transmission isobtained by analyzing the efective medium theory and the EM fields. The solutions holdfor lossy case in a quite large frequency range. We also propose a force-inducedtransformational device, which can realize dynamic cloak. Based on transformation opticsand the force-induced anisotropy of photoelastic material, the proposed device cancontinuously change the effective plane and-preserve phase of reflected wave at the same time.3. Anisotropy-induced Fano resonance on infinite long cylinderWe adopt the fullwave electromagnetic theory to study the scattering of anisotropiccylinder. We demonstrate that optical Fano resonance can be induced by birefringenceunder the resonant condition. A tiny perturbation in birefringence can result in a giantswitch in the principal optic axis near surface Plasmon resonance. Suchbirefringence-induced Fano resonance shows fast-reversion between forward scatteringand backward scattering. The topology of optical singular points and the trajectory ofenergy flux reveal distinctly the interaction between incident waves and localized surfacePlasmons.4. The optical force on sphere particlesWe demonstrate large negative forces on plasmonic nanostructure by using dipoleapproximation and precise full-wave Mie theory. The plasmonic nanostructure shows about20times lager optical pulling force than a same size of gain sphere at surface plasmonresonance and plasmon singularity. Even greater negative force arises at higher-orderresonance when the nanostructure’s size is increased. In addition, we study optical force onA dielectric sphere by a nonparaxial Bessel beam. We extend the known far-fieldexplanation of the pulling force phenomenon by light beams to the analysis in the nearfield. Our work reports new insight in topological optical singularities of the Poyntingvector. The negative optical pulling force as the consequence of the transfer of the storedazimuthal component of the Poynting vector to the longitudinal component. The results canbe useful for analyzing optical forces acting on a number of particles.