共查询到20条相似文献,搜索用时 15 毫秒
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The structural dispersion characteristics of guided surface modes in a hollow slab waveguide with a left-handed material substrate or cover are investigated. Dispersion relation is derived by using normalized parameters, and universal dispersion curves have been obtained analytically, by solving transcendental dispersion equations in a reverse way. Existence condition, mode degeneracy and other dispersion properties of guided surface modes have been discussed for different ? or μ of three layers for this substrate or cover layer. 相似文献
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Daniel Pasquet 《International Journal of Infrared and Millimeter Waves》1982,3(2):159-169
The continuous modes in hollow dielectric wavegudes and in a free space are described in the case of slab and cylindrical structures. The continuous modes in free space are compared with gaussian modes, in particular for the output beam of a slab FIR laser. 相似文献
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Daniel Pasquet 《International Journal of Infrared and Millimeter Waves》1981,2(3):453-463
We propose a graphic method for the resolution of the characteristic equations of a hollow slab waveguide. The variations of the complex inner transverse wave number is described. The validity of oversizing approximation is discussed. It is proved that an active mode is necessarily proper. 相似文献
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Daniel Pasquet 《International Journal of Infrared and Millimeter Waves》1981,2(6):1151-1163
The characteristic equation is solved for oversized slab and cylindrical hollow waveguides. The outter medium is a dielectric or a metal for cylindrical waveguides, and a dielectric for slab waveguides. The results are applied to consider the resonance conditions for a FIR laser cavity. 相似文献
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从电磁场理论出发对负折射材料填充的3层平板波导的传播特性进行研究,并进行了数值计算,分析TE和TM波在平板中传播的性质,得到了电磁波的模式方程,与电磁波在右手材料填充的平板波导中的传播特性做了对比,考察了TE模式的能流密度,进行了归一化计算。结果分析表明:基模、一阶模不存在,且任何模式都存在一个截止厚度,随着厚度的增大,模式数量也增多;在一定的入射频率下,平板薄膜厚度趋向一定数值时,可以同时传播多种模式的波,并且入射波频率越高,波导同时存在多种模式的可能性越大;与右手材料相比,左手材料填充相同尺寸的3层平板波导可以传播更高能量的电磁波,导波效果更好。 相似文献
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Jie Li 《Optics Communications》2008,281(23):5797-5803
By means of a zigzag-wave model, we perform a comprehensive analysis of the guided modes of a photonic bandgap slab waveguide that consists of a low-index guiding layer placed between two different Bragg reflectors. We show that the guided modes of the waveguide operate inside the overlapped bandgaps of the two Bragg reflectors. We label each mode with three mode orders, which reflect the features of the mode-field distribution in the guiding layer and the two Bragg reflectors, respectively. We discuss in detail the transmission characteristics of the guided modes, including the dispersion curves, the cutoff conditions, and the confinement factors, and highlight the mode-selection characteristics of the waveguide. We also study the effects of truncating the Bragg reflectors by deriving an analytical expression to show the dependence of the leakage losses of the modes on the numbers of the periods in the truncated Bragg reflectors. 相似文献
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A. Tseronis D. Tsilimantos N. Uzunoglu 《International Journal of Infrared and Millimeter Waves》2005,26(2):279-295
Radiation phenomena observed in a wedge shape ended dielectric slab waveguide are analyzed using mode matching technique. The case of transverse electric polarization (TE) being parallel to dielectric slab waveguide is assumed. In order to describe the fields in the wedge region, a stack of dielectric plates is assumed and in each layer the fields are expanded in terms of the mixed spectrum of guided and radiated modes. A similar expansion is used in the constant thickness slab waveguide while in free space medium a continuous-radiation mode expansion is used. Then a mode matching approach is applied, incorporating the orthogonality properties of mixed spectrum modes, in order to compute the wave fields inside the dielectric slab waveguide and wedge medium. Mode matching is achieved by discretizing the continuous radiation mode spectrum leading into a numerically stable solution provided a sufficient large number of points are used to convert integrals into finite summations. Numerical computations are carried out for various wedge geometries and shapes including linear and exponential profiles. 相似文献
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利用椭圆形孔替代传统光子晶体薄板波导中邻接波导的最内层两排圆孔构成一种新型低损耗光子晶体薄板光波导.该波导的群速度和群速度色散特性强烈依赖于波导中这两排邻接波导的椭圆孔的特性.借助波导导模展开方法,计算得到波导的能带结构和群指数,并分析了它们与椭圆孔的参数关系.通过优化这些椭圆孔的参数,可以增加光子晶体光波导导模在光锥以下的无固有传输损耗带宽,在2—45 nm 的带宽上实现无色散的常数群速度.这些理论结果将为低损耗低色散慢光波导的设计制造提供理论基础.
关键词:
光子晶体薄板波导
群速度
群指数
群速度色散 相似文献
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提出采用不可逆封合技术来解决可逆封合的平面光波导生物传感器的微流通道在注入液体压力较大时会出现漏液的问题。分别采用等离子体法、氧化法、紫外灯照射法和紫外胶法实现了聚二甲基硅氧烷(PDMS)和绝缘材料上的硅(SOI)波导的不可逆封合。首先,采用4种实验方案分别处理PDMS和SOI波导表面,测试了经上述几种方法处理后微流通道与波导的粘合能力的强弱。然后,定量分析PDMS和SOI波导的封合效果。最后,经过实验比较得出用等离子体处理PDMS和SOI波导表面得到的不可逆封合效果最好的结论。文中也讨论了其他实验因素对粘合程度的影响。 相似文献
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利用椭圆形孔替代传统光子晶体薄板波导中邻接波导的最内层两排圆孔构成一种新型低损耗光子晶体薄板光波导.该波导的群速度和群速度色散特性强烈依赖于波导中这两排邻接波导的椭圆孔的特性.借助波导导模展开方法,计算得到波导的能带结构和群指数,并分析了它们与椭圆孔的参数关系.通过优化这些椭圆孔的参数,可以增加光子晶体光波导导模在光锥以下的无固有传输损耗带宽,在2—45 nm 的带宽上实现无色散的常数群速度.这些理论结果将为低损耗低色散慢光波导的设计制造提供理论基础. 相似文献
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We report a low-loss photonic crystal slab waveguide formed by deforming the innermost circle air holes in the conventional photonic crystal slab waveguide into elliptical ones. We obtain the photonic bands and group index of guided modes in this photonic crystal waveguide by guided-mode expansion method and investigate the dependence of photonic bands and group index of guided modes on the parameters of the innermost elliptical air holes. The group velocity and group velocity dispersion of this waveguide strongly depend on the innermost elliptical air holes. Photonic crystal slab waveguide with the optimum innermost elliptical air holes possesses a wider single mode region below the light line, in which light can easily propagate without intrinsic loss. At the same time, the guided mode supported by this waveguide has nearly constant group velocity and vanishing group velocity dispersion in a 3-5 nm bandwidth. 相似文献
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Dajun Cheng Liangjin Xue 《International Journal of Infrared and Millimeter Waves》1991,12(12):1461-1467
Radiation of an electric dipole located along an arbitrary direction in the presence of a chiral slab is formulated using matrix analysis in conjunction with Fourier transform techniques. Moreover, dyadic Green's function of such a structure may be determined for further investigation porpose. 相似文献