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A simple and comprehensive electromagnetic theory uncovering complete picture of light transport in birefringent crystals 下载免费PDF全文
Jianbo Pan 《中国物理 B》2022,31(5):54201-054201
Birefringence production of light by natural birefringent crystal has long been studied and well understood. Here, we develop a simple and comprehensive rigorous electromagnetic theory that allows one to build up the complete picture about the optics of crystals in a friendly way. This theory not only yields the well-known refraction angle and index of ellipse for birefringence crystal, but also discloses many relevant physical and optical quantities that are rarely studied and less understood. We obtain the reflection and transmission coefficient for amplitude and intensity of light at the crystal surface under a given incident angle and show the electromagnetic field distribution within the crystal. We derive the wavefront and energy flux refraction angle of light and the corresponding phase and ray refractive index. We find big difference between them, where the phase refractive index satisfies the classical index of ellipse and Snell's law, while the ray refractive index does not. Moreover, we disclose the explicit expressions for the zero-reflection Brewster angle and the critical angle for total internal reflection. For better concept demonstration, we take a weak birefringent crystal of lithium niobate and a strong birefringent crystal tellurium as examples and perform simple theoretical calculations. In addition, we perform experimental measurement upon z-cut lithium niobate plate and find excellent agreement between theory and experiment in regard to the Brewster angle. Our theoretical and experimental results can help to construct a clear and complete picture about light transport characteristics in birefringent crystals, and may greatly facilitate people to find rigorous solution to many light-matter interaction processes happening within birefringent crystals, e.g., nonlinear optical interactions, with electromagnetic theory. 相似文献
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采用溶胶-凝胶法制备了双稀土掺杂氧化铈Ce_(0.8)Pr_(0.2-x)Nd_xO_(2-δ)(x=0.02,0.05,0.1)固溶体。X射线衍射分析阐明,经800℃烧结的全部固溶体都形成了单相立方萤石结构,平均晶粒尺寸在20~25 nm之间。拉曼光谱结果阐明,固溶体Ce_(0.8)Pr_(0.2-x)Nd_xO_(2-δ)是具有氧空位的立方萤石结构,适量的掺杂Nd有利于Ce_(0.8)Pr_(0.2-x)Nd_xO_(2-δ)氧空位浓度的增加。阻抗谱结果阐明,稀土双掺杂的Ce_(0.8)Pr_(0.2-x)Nd_xO_(2-δ)比稀土单掺杂的Ce_(0.83)Sm_(0.17)O_(2-y)的电导率高,Ce_(0.8)Pr_(0.18)Nd_(0.02)O_(2-δ)的电导率最大,600℃时电导率为1.85×10~(-2)S/cm。 相似文献
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We present a discovery of an unusual unidirectionally rotating windmill scattering of electromagnetic waves by a magnetized gyromagnetic cylinder via an analytical theory for rigorous solution to fields and charges and an understanding of the underlying mathematical and physical mechanisms. Mathematically, the generation of nonzero off-diagonal components can break the symmetry of forward and backward scattering coefficients, producing unidirectional windmill scattering. Physically, this windmil... 相似文献
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Topological photonic states in gyromagnetic photonic crystals: Physics,properties, and applications 下载免费PDF全文
Jianfeng Chen 《中国物理 B》2022,31(11):114207-114207
Topological photonic states (TPSs) as a new type of waveguide state with one-way transport property can resist backscattering and are impervious to defects, disorders and metallic obstacles. Gyromagnetic photonic crystal (GPC) is the first artificial microstructure to implement TPSs, and it is also one of the most important platforms for generating truly one-way TPSs and exploring their novel physical properties, transport phenomena, and advanced applications. Herein, we present a brief review of the fundamental physics, novel properties, and practical applications of TPSs based on GPCs. We first examine chiral one-way edge states existing in uniformly magnetized GPCs of ordered and disordered lattices, antichiral one-way edge states in cross magnetized GPCs, and robust one-way bulk states in heterogeneously magnetized GPCs. Then, we discuss the strongly coupling effect between two co-propagating (or counter-propagating) TPSs and the resulting physical phenomena and device applications. Finally, we analyze the key issues and prospect the future development trends for TPSs in GPCs. The purpose of this brief review is to provide an overview of the main features of TPSs in GPC systems and offer a useful guidance and motivation for interested scientists and engineers working in related scientific and technological areas. 相似文献
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采用硅胶柱色谱,Sephadex LH-20凝胶柱色谱及HPLC等方法从昆虫共生真菌Alternaria sp.(Be-1)的发酵液分离得到7个代谢产物,经NMR,MS及理化性质等确定为4个环肽和3个聚酮类化合物,4-甲氧基格链孢酚(1),5'-methoxy-6-methyl-biphenyl-3,4,3'-triol(2),altenusin(3),二氢腾毒素(4),腾毒素(5),环(4-羟基-脯-亮)二肽(6)和cyclo(L-Phenylalanine-trans-4-hydroxy-L-proline)(7)。测定了化合物1-7对抗肿瘤治疗靶点-受体酪氨酸激酶的抑制活性,药理实验结果表明,化合物1-6对三种酪氨酸激酶(EGFR,VEGFR-1,c-Met)具有不同程度的抑制活性,化合物1,3,6对EGFR,VEGFR-1,c-Met均具有强的抑制作用,而且化合物6还有选择性抑制EGFR和c-Met的活性。 相似文献
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