共查询到16条相似文献,搜索用时 125 毫秒
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含单负材料的不对称平板波导的传导模 总被引:2,自引:0,他引:2
利用图解法系统地研究了由不同类型的单负材料作为包层的三层平板波导的模式特征.研究表明单负介质波导具有一系列奇异的特性,与传统介质波导或左手介质波导相比,此波导的芯区横向振荡导模的模折射率范围较大.除0阶导模外,其它TE,TM导模均为芯区横向振荡模,且同阶的TE、TM模的色散曲线几乎重合,只有0阶的TE,TM模才可以支持表面波的传播.单负介质的结构参数对0阶导模的影响较大.一定条件下,波导中可以出现0阶导模的完伞缺失或仅支持表面波的传输,还会出现超慢波现象,甚至可以共生都是后向波的0阶双模. 相似文献
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对芯层为左手材料而内外包层都是普通材料的非对称三层平面波导TE振荡模进行了分析.在考虑左手材料色散和各向异性的情况下,从Maxwell方程组出发,得到了TE振荡模的色散方程和功率流分布,并且画出了相应的色散曲线.我们找到了8个TE振荡模,而且包括基模.随着模阶数的增加,模色散曲线右移,功率流曲线下移.但是,随着波导厚度的增加,色散曲线左移,功率流曲线上移.此外,TE振荡模有反常色散特性和负的群速,这正揭示了左手材料的本质特性. 相似文献
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对芯层为左手材料而内外包层都是普通材料的非对称三层平面波导TE振荡模进行了分析.在考虑左手材料色散和各向异性的情况下,从Maxwell方程组出发,得到了TE振荡模的色散方程和功率流分布,并且画出了相应的色散曲线.我们找到了8个TE振荡模,而且包括基模.随着模阶数的增加,模色散曲线右移,功率流曲线下移.但是,随着波导厚度的增加,色散曲线左移,功率流曲线上移.此外,TE振荡模有反常色散特性和负的群速,这正揭示了左手材料的本质特性. 相似文献
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转移矩阵法在负折射率介质材料平板波导中的应用研究 总被引:3,自引:3,他引:0
利用严格电磁理论,推导出了适用于负折射率介质材料光波导的转移矩阵,分析讨论了转移矩阵的性质和应用.利用转移矩阵方法,推导出导波层为负折射率介质材料、覆盖层和衬底为右手材料的三层对称介质光波导的本征色散方程.用图解法研究了负折射率介质波导中TE波的异常色散特性.在负折射材料介质波导中没有零阶模,最低阶为1阶模,并且有截止频率,只有波导参量满足一定条件的时候才会存在,导模的横向波数可以为实数和纯虚数,而正折射率介质波导导模的横向波数只能为实数. 相似文献
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电磁波在负折射材料填充的3层平板波导中的传播特性 总被引:1,自引:1,他引:0
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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对于晶体光轴平行于波导界面的结构,讨论了光在金属包层对称平面单轴晶体波导(波导层是单轴晶体,两个波导界面均为金属)内的传输特性.解析地得到了这种结构下波导模式场的精确解.模式场的性质因单轴晶体的性质不同而异.对于正单轴晶体,波导的主模是横电波,任何频率的光波均可激励该模式;当频率满足一定条件时,波导内传输单模,否则,将激励起高阶模式.高阶模既非TE波,也非TM波,而是两者耦合而成的混合模.对于负单轴晶体,波导的主模是一种混合模,该模式同样可被任何频率的光波所激励;当频率满足一定条件时,波导内传输单模,否则
关键词:
平面金属波导
单轴晶体
模式场
混合模 相似文献
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We study guided modes propagating along a dielectric slab waveguide with a left handed material (LHM) cover or substrate. The dispersion relation is derived by using normalized waveguide parameters. An analytical method is then proposed to calculate the universal dispersion curves. Different from a slab waveguide with a LHM core, we find that guidance properties are strongly dependent on dielectric permittivity ε and magnetic permeability μ of the substrate and cover layers. For oscillating guided modes, fundamental zero order mode is not always absence, sometimes it exists in a restricted range of normalized propagation constant. First order mode behaves as other higher order modes and exists up to infinite high frequency. Higher order modes have no double degeneracy in the case of LHM cover layer. For surface guided modes, the existence and the type of the mode solutions with respect to different parameters are classified systematically and discussed in detail. Unlike a slab waveguide with a LHM core where the dispersion curve of TE1 surface mode continues with that of oscillating TE1 mode, the dispersion curve of TE1 surface mode continues with that of oscillating TE0 mode. It seems that the two different kinds of modes compensate each other to form one whole mode. Both TE and TM guided modes are discussed. 相似文献
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We investigate guided modes in the asymmetric waveguide structure with a left-handed material (LHM) layer surrounded by air and metal. A graphical method is proposed to determine the guided modes. New properties of the oscillating and surface guided modes, such as absence of the fundamental mode, coexistence of the oscillating and surface guided modes, fast attenuation of the surface guided modes, and mode degeneracy, are analyzed in detail. We also investigate dispersive characteristics of the metal-LHM- air optical waveguide. The propagation constant increases with decreasing slab thickness for the first-order oscillating mode, which is different from that in traditional metal-cladding waveguides. 相似文献
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A new dielectric slab waveguide with a left-handed material (LHM) cover and substrate is proposed. The dispersion relations
and normalized effective thickness of the asymmetric LHM slab waveguide are investigated, in view of the normalized parameters.
A number of unusual properties are found, for example, the fundamental and first-order modes do not exist and higher-order
modes have double degeneracy. The propagation modes are absent at the low normalized frequency, and the cutoff frequencies
of some LHM slab waveguide modes decrease with increase in the asymmetry measure. Unlike traditional slab waveguides, the
V –H curves of the LHM slab waveguides are in one-to-one correspondence. Both TE and TM modes are discussed; in addition, the
dispersion relations and normalized effective thicknesses of the TM modes are discussed in detail, when the difference in
refractive indices of the film and the substrate is small. The results show that the region of mode coexistence taking place
near the cutoff frequency becomes narrower with increase in the difference in refractive indices of the film and the substrate.
The influence of this difference on the normalized effective thickness curves is different, and becomes smaller and smaller
with increase in the value of the asymmetry measure, if different values of the refractive indices are employed. 相似文献
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Jin Tae Kim 《Optics Communications》2011,284(18):4171-4175
It has been experimentally demonstrated that a low-loss guided hybrid mode is supported if a metal strip is embedded in a low index polymer layer surrounded by two high index slabs. In this paper, further numerical analyses on the guided hybrid modes are reported to fully elucidate the characteristics of the hybrid plasmonic waveguide. For a one-dimensional slab structure with a metal film of infinite width, simulation results exhibit that low-loss guided hybrid modes are associated with surface plasmon modes and dual dielectric slab modes. The optical properties of the guided modes are improved by increasing the field intensity which is confined into lossless dielectric layers by decreasing the metal film thickness and increasing the refractive index and thickness of the high-index slabs. The finite element method is used to investigate the lateral mode confinement of the optical guided modes by the corresponding metal strip. By reducing the metal film width, the guided modes are confined in the plane transverse to the direction of propagation and the characteristics are significantly improved. The hybrid plasmonic waveguide can be exploited for long-range propagation-based application such as optical interconnection. 相似文献