【作者】 王海峰；

【导师】 周忠祥；

【作者基本信息】 哈尔滨工业大学 ， 光学， 2010， 博士

【摘要】 多层膜微结构可应用于集成光学、电光开关、传感器等,在制造光电检测器件方面有重要应用前景。包含金属、液晶和左手材料膜层的多层膜微结构的光学特性吸引了众多研究者的关注,目前在精密测量、超棱镜和调制器方面都取得了一定的进展。多层膜微结构的古斯-汉欣(GH)效应成为当前传感器和光电检测领域的研究热点。本文主要研究不同多层膜结构对GH位移的增强作用和外加电场对GH位移的调制作用。采用静态相位法研究由不同材料组成的多层膜光学微结构的古斯-汉欣位移特性,利用高斯光束法分析窄光束入射对反射场分布的影响,进一步验证静态相位法计算结果的有效性。表面等离子共振现象已经被广泛研究,结合晶体的线性电光效应,研究了通过外加电场调节古斯-汉欣位移的可能性。对所研究的结构,分析了表面等离子波的色散关系和传播常数,给出了系统的本征损耗和辐射损耗,发现只有本征损耗大于辐射损耗时, GH位移才能是负的。推导了系统反射光的反射率、相位、GH位移随入射角和外加电压的变化,计算结果表明电压调制和角度调制的结果相同,在试验中电压调制可取代角度调制。通过对左、右手材料组成的三层膜结构的研究,分析了左、右手材料组成的界面的部分反射和全反射,给出了振幅反射率的统一描述公式,由此计算了三层结构的振幅反射率。在此基础上利用静态相位公式计算了GH位移,发现这种结构GH位移的正负仅取决于前两层介质的手性参数,手性参数相同则GH位移为正,手性相反则GH位移为负。推导了含弱吸收介质的三层介质结构的反射公式,分析了系统的本征损耗和辐射损耗,给出了泄漏导波共振条件附近的反射率表达式,发现共振时,若本征损耗等于辐射损耗,则系统的反射率为零,说明入射光的能量全部被耦合到弱吸收介质层中。在此基础上,利用静态相位公式给出了共振条件附近的GH位移表达式。进而计算了反射光的反射率、相位、GH位移随入射角度、损耗参数及弱吸收膜层厚度的关系。发现反射率在共振条件形成吸收峰, GH位移可正可负,并可被增强到1500个波长。用高斯光束法计算了束腰宽度有限时反射场分布,在宽光束入射时计算结果与静态相位法的结果相一致,同时也发现共振时反射光场形成双峰分布,因此工作点只能选在共振条件附近。利用旋转矩阵法,给出了液晶中指向矢与坐标轴有夹角时的介电常数和磁导率张量。在此基础上确定了横磁波在液晶中的色散关系。并利用Maxwell方程组和边界条件,求出了含液晶多层膜结构的振幅反射率。利用时间平均的坡印亭矢量,给出了在晶体和介质界面发生负折射的条件,与晶体物理学中的分析结果一致。结合静态相位公式,计算了双棱镜包夹液晶层结构的GH位移,发现调节入射角度和调节外加电压都可以实现对GH位移的调制,并且GH位移可正可负。设计了双面金属包覆液晶的结构,利用自由空间耦合技术和双面金属波导,实现了对GH位移的增强。计算了系统反射光的反射率、相位和GH位移随入射角度及外加电压的变化。分析了入射光束腰宽度对GH位移的影响,验证了静态相位法计算结果的有效性。更多还原

【Abstract】 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.更多还原