Study On Excitation And Properties Of Surface Plasmon Polaritons At Metal-Uniaxial Dielectric Interface

Surface plasmon polariton (SPP) is a resonant excitation of a coupled state between the plasma oscillations and the photons. It has field enhancement and localization effect in nano scales, and its transmission wavelength is smaller than the wavelength of the light transmitting in free space. It is the combination of plasmonics and crystal optics that makes the SPP possess the characteristics of the optical anisotropy, polarization diversity, and the dynamic adjustment at interface between metal-anisotropic dielectric. Increasing of mi-cro/nano machining technology for the preparation of anisotropic dielectric material offers more possibilities. These advantages provide new ideas for the research of future miniatur-ization, dynamic tunable photonic devices and nano chip photoelectric integrated device. In this dissertation, we will study the abnormal total reflective at the interface between an isotropic medium and a uniaxial dielectric, the complete dispersion relation of transverse magnetic(TM) SPPs at a metal-uniaxial dielectric interface, and the excitation and prop-erties of hybridized SPPs at interface of a metal and a uniaxial dielectric, with the optical axis in arbitrary orientation. Taking advantage of finite-difference time-domain(FDTD) method, we verify the theoretical results. The main researches and achievements of this thesis are summarized as following:Firstly, we theoretically study the excitation of conditions and the physical mech-anism of abnormal total reflection when a plane wave is incident from a rare isotropic medium to a dense anisotropic uniaxial dielectric with optical axis oriented arbitrarily in three-dimension space. For the relationship between orientation of optical axis and condi-tions of the total reflection at isotropic dielectric-uniaxial dielectric interface, through the geometries of dispersion surface(curves) of the same frequency electromagnetic waves in the uniaxial dielectric, the physical model of the abnormal total reflection is established in the incident plane, and then the necessary conditions of the abnormal total reflection to occur are derived. The simulation of this abnormal phenomenon of total reflection is carried out taking advantage of FDTD Solution, and verify the necessary conditions. In addition, the dependence of the abnormal total reflection of the feasible region and its critical angle is discussed, and the smaller critical angles of abnormal total reflection are analyzed.Secondly, we theoretically study the complete dispersion of TM SPPs(along and normal to the interface, respectively) at a metal-uniaxial interface, and realize the surface wave completely attenuated normal to the interface. For the case of optical axis parallel to the plane of the normal to the interface and the direction of the propagation of SPP, uti-lized the boundary conditions of electromagnetic field, the exact solution of the Maxwell equations in the metal and the uniaxial dielectric are derived analytically. According to the direction of the wave vector of the SPP in the vertical direction, the transmission char-acteristics, depth of penetration and energy flow of these modes are demonstrated. Two new TM SPPs are found. Using the loss of metal and the anisotropy of the real uniaxial dielectric, the "perfect" surface waves can realize at the interface between the loss metal and a real uniaxial dielectric.Lastly, the excitation and properties of hybridized surface plasmonics polaritons is studied. In the uniaxial dielectric cladding-metal-dense isotropic dielectric structure—— Kretschmann configuration, the reflection formulation R(θi,φ) of the Kretschmann con-figuration is derived with TM plane source and beam propagation method. For the case of the optical axis parallel to the metal-uniaxial dielectric interface, the validity of the expression of the reflectivity are confirmed by the FDTD method and the reported exper-imental results. The resonance wavelengths of three results agree very well. In addition, under the same conditions of the configuration and parameters of materials as the reported paper, the reflectance spectra of the resonant wavelength variation with optical axis ori-entation by calculation of our reflection formula, agree very well with the reported results in the paper. These comparisons indicate the validity of our reflection formula. In the same Kretschmann configuration, the excitation efficiency of the source of the transverse electric(TE) polarized plane wave is lower than the TM one. On the other hand, the distri-bution of electric field vector and polarization states of two type of hybridized SPP (non-radioactive hybridized SPP and quasi-guided hybridized SPP) are analyzed in details. For the cases of the strongly anisotropic positive cladding, the strongly anisotropic negative cladding, and weakly anisotropic one, reflectance spectra R(kx, ky) of the Kretschmann are configuration simulated numerically by our analytical formula, respectively. The physics to excite hybridized SPP is elucidated so that the conditions for excitation of hybridized SPP are predicted by the total reflection angle spectra and TE reflection angle spectra.