Study Of Exciting Structures And Optical Characterizations On Goos-h ¨ Anchen Effect

Multi-layer micro-structure can be applied to integrated optics, electro-opticalswitches, sensors and so on, in the manufacture of photoelectric detection device has animportantapplicationprospect. Theopticalpropertiesofmulti-layermicro-structure(con-tainingmetals,liquidcrystal,orleft-handedmaterials)haveattractedtheconcernsofmanyresearchers, who have made some progress in precision measurement, super-prism, andmodulators. The Goos-H¨anchen (GH) effect of multi-layer micro-structure is one of se-lected areas in the field of sensors and photoelectric detection researches. In this thesis,we study the different multi-layer structures to enhance the amplitude of the GH shift andtake use of the applied electric field for modulation of the GH shift. For multi-layer opti-calmicro-structurecomposedofvariousmaterials, thecharacteristicsoftheGHshifthavebeen investigated by the stationary-phase method. The reflected field distribution of anincident narrow beam has been calculated by the Gaussian-beam method, furthermore thevalidity of results is verified.SPR phenomenon has been extensively studied, combined with the linear electro-optic effect of crystal, the possibility of tuning GH shift by external electric field has beeninvestigated. For the studied structure, we analyze the dispersion relation of the surfaceplasma wave and propagation constant, give the internal damping and radiation damping.It is found that only when the internal damping is larger than radiation damping, GH shiftcan be negative. The dependences of reflectivity, phase, and GH shift on the angle ofincidence and the applied voltage are derived; the calculated results show that results ofthe voltage modulation and angle modulation are the same, in the experiments the anglemodulation can be replaced by voltage modulation.Through the research of three-layer structure composed of the left and right-handedmaterial, we analyze partial reflection and total reflection at the interface of the left andright-handed material, give a unified description of the amplitude reflectivity formula,then calculate the amplitude reflectivity of the three-layer structure. On this basis, the GHshift is calculated by the stationary-phase method and it is found that for this structure thesign of the GH shift depends only on the hand-parameters of the first two medium, whichare the same and the GH shift is positive, otherwise the GH shift is negative. For the three-layer structure containing a weakly absorbing medium, by the analysisof the system's internal damping and radiation damping, the reflectivity expression of theleaky waveguide is given in the vicinity of the resonant conditions. It is found that atresonance, if the internal damping is equal to the radiation damping, the reflectivity of thesystemiszero, indicatingthatalltheenergyoftheincidentlightiscoupledintotheweaklyabsorbing layer. The GH shift expressions are given by a stationary-phase formula. Thenthe dependences of the reflectivity, phase, GH shift of the reflected light, on the incidentangle, the loss parameter and thickness are calculated. It is found that an absorption peakof reflectivity is formed at resonance, GH shift can be positive or negative, and evencan be enhanced to 1500 wavelengths. The reflected field distribution is calculated byGaussian-beam method, the results are consistent with the results by the stationary-phasemethod when the incident beam is wide, but the operating point can only be chosen nearthe resonance condition due to the formation of null reflection at resonance.The dispersion relation of TM wave is determined in the liquid crystal. For multi-layer structure with a nematic liquid crystal (NLC) film, the amplitude reflectivity is ob-tained by Maxwell equations and boundary conditions. The time-averaged Poynting vec-tor gives the conditions for negative refraction that occurs at the interface, which are con-sistent with the analysis in crystal physics. Combinating a stationary-phase formula, theGH shift is calculated for the double-prism structure with a liquid crystal layer, it is foundthat the GH shift can be modulated by both the applied voltage and incident angle, andthe GH shift can be positive or negative. A structure of a symmetric metal-cladding liquidcrystal, by use of the free-space coupling technique and metal-cladding waveguide tech-nique, GH shift can be enhanced. The dependences of the reflectivity, phase and GH shiftof the system on the applied voltage and the incident angle are calculated. The influenceof the waist width of incident light on the GH shift is analyzed, and the validity of thestationary-phase method is verified.