共查询到20条相似文献,搜索用时 218 毫秒
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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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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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报道了中心对称光折变晶体与线性电介质界面表面波的形成及能量变化. 通过调节传播常数和波导参数的方法,可以得到非局域、振荡、局域三种类型的表面波. 波导参数和传播常数之差大于阈值时,线性电介质和中心对称光折变晶体界面可以形成局域表面波. 波导参数为正值时,局域表面波主要聚集在中心对称光折变晶体内,随着传播常数的增大,波能量随之单调递增,表面波可以稳定传播. 在给定的条件下,调节决定非线性作用强度的可变参量可以控制局域表面波模的阶数和传播波形.
关键词:
非线性光学
中心对称光折变晶体
表面波 相似文献
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We investigate theoretically the creation conditions of TE and TM polarized surface waves created at the interface between a homogeneous medium and one dimensional photonic crystal (1D PC). The 1D PC is composed of uniaxially anisotropic left-handed (LH) and isotropic right-handed (RH) layers. We show that the characteristics of surface waves created in the 1D PC are significantly different from those created in the structure composed of isotropic LH and RH layers. We also prove that the coexistence of TE and TM surface waves at the interface is possible in the same frequency domain. Moreover, it is shown that in this structure backward and forward surface waves are created in wider ranges of frequency and angle of incident light, in comparison with the structure in which the left-handed layers are isotropic. 相似文献
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We study the electromagnetic surface wave localizing, the so-called surface Tamm states, at an interface separating a left-handed metamaterial (LHM) and a semi-infinite one-dimensional photonic crystal made of alternative left-handed metamaterial and right-handed materials. We show that the existence of metamaterial causes the Tamm states with backward energy flow and allows flexible control of dispersion properties of the surface modes. We study the effect of the physical parameters of the photonic crystal on the dispersion properties and the group velocity of the Tamm states. We also study dispersion properties of the Tamm states in higher order photonic band gaps of the photonic crystal and compare our results with the case when the LHM medium is replaced by a right-handed material (RHM). 相似文献
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We report the coexistence of TE and TM surface modes in certain same
frequency domain at the interface between one isotropic regular medium and
another biaxially anistotropic left-handed medium. The conditions for the
existence of TE and TM polarized surface waves in biaxially anisotropic
left-handed materials are identified, respectively. The Poynting vector and
the energy density associated with surface modes are calculated.
Depending on the system parameters, either TE or TM surface modes can
have the
time averaged Poynting vector directed to or opposite to the mode phase
velocity. It is seen that the characteristics of surface waves in biaxially
anisotropic left-handed media are significantly different from that in
isotropic left-handed media. 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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Prabhakaran Letha Premlal Dinesh Chandra Tiwari Vandana Chaturvedi 《The European Physical Journal B - Condensed Matter and Complex Systems》2018,91(5):78
We present a detailed theoretical analysis about the influence of surface polaritons on the transmission properties of electromagnetic waves at the periodically corrugated interface between the vacuum and left-handed material by using nonlinear boundary condition approach. The principle behind this approach is to match the wave fields across the grating interface by using a set of linear wave equation with nonlinear boundary conditions. The resonant transmission of the incident electromagnetic radiation in this structure is feasible within a certain frequency band, where there is a range of frequency over which both the electric permittivity and the magnetic permeability are simultaneously negative. The enhanced transmission is attributed to the coupling of the incident electromagnetic wave with the excited surface polaritons on grating interface. Finally, we present the numerical results illustrating the effect of the structural parameters and angle of incidence on the transmission spectra of a TM polarized electromagnetic wave. 相似文献
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The TE/TM polarization conversion characteristics of dielectric grating composed of left-handed materials for the case of
plane wave oblique incidence are carefully investigated by a method which combines the multimode network theory with the rigorous
mode matching method. It is indicated that complete polarization conversion between TE and TM modes can be realized using
left-handed gratings. This can hardly achieve in the conventional right-handed gratings. Comparisons of polarization conversion
properties between right-handed gratings and left-handed gratings are given with physical explanations. This unique merit
of left-handed periodic structure is of important significance for accurate design of new millimeter wave TE/TM polarization
converters. 相似文献
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In this paper, we investigate the electromagnetic surface waves localized at the interface of the homogeneous dielectric medium and a semi-infinite one-dimensional photonic crystal (1D PC), theoretically. The semi-infinite 1D PC is made of alternative layers of left-handed (LH) and right-handed (RH) materials in the presence of a thin nonlinear cap layer. We consider magnetic permeability and electric permittivity of LH layers being dispersive and non-dispersive. We used an analytical direct matching procedure within the Kronig-Penny model to analyze the dispersion behavior of surface waves with controllable localization. It is shown that the thin nonlinear cap layer acts as a tool to change the backward surface waves to forward ones and vice versa and it plays an important role on the localization of them. Also we show that when the LH layers are chosen dispersive, negative dispersion of surface waves are obtained in a wide range of radiation angle and frequency, and we propose an approach to calculate the applied electric field intensity that leads to switching of surface waves from backward to forward and creating a surface mode with maximum localization. 相似文献
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The coexistence of TE-TM surface waves in uniaxially anisotropic left-handed materials 总被引:1,自引:0,他引:1
We investigate theoretically the characteristics of surface waves in uniaxially anisotropic left-handed materials. The constraints for the existence of TE and TM polarized surface waves in uniaxially anisotropic left-handed materials are identified. We discuss mainly whether TE and TM polarized surface modes may coexist in the same frequency domain at the interface between one isotropic regular medium and another uniaxially anisotropic left-handed medium. It is shown that the answer to the coexistence of TE and TM surface modes is really positive. The Poynting vector and the density of energy associated with surface modes are calculated. Depending on the system parameters either TE or TM surface modes has the time averaged Poynting vector directed opposite or same to the mode phase velocity. In the presence of anisotropy, negative refraction does not need to be left-handed. We show that the characteristics of surface waves in uniaxially anisotropic left-handed media are significantly different from that in isotropic left-handed media. 相似文献
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在理想条件下,为了研究等离子体参数、填充率、入射角度和介质层相对介电常数对一维三元磁化等离子体光子晶体的禁带特性的影响,用由传输矩阵法计算得到的TE波任意角度入射时的左旋极化波(LCP)和右旋极化波(RCP)的透射系数来研究其禁带特性。结果表明,仅增加等离子体碰撞频率不能实现禁带宽度的拓展,改变等离子体频率、填充率和介质层的相对介电常数能实现对禁带宽度和数目的调谐。改变等离子体回旋频率能实现对右旋极化波的禁带的调谐,但对左旋极化波的禁带几乎无影响。入射角度的增大使得禁带低频区域带宽变大,而高频区域带宽则是将先减小再增大。 相似文献