共查询到20条相似文献,搜索用时 15 毫秒
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Abstract The optical characteristics of the TE and TM guided modes of a multilayer anisotropic two-dimensional waveguide are investigated by using the field component transformation matrix, and also taking into account the substrate intrinsic dispersion. The embedded thin metal layer effects on the propagation constant for both lossless approximated and exact solutions are presented. The lossless approach is accurate enough for the TE waves, but it is not for the TM ones, which exhibit changes of about 10?6 for the equivalent index. The TM modes also present attenuation constant changes between the lossy and weakly-lossy solutions of the order of 9 dB/cm. Several complex field component mappings are drawn, and the surface plasma waves are also examined. 相似文献
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T. G. Theodoropoulos I. G. Tigelis 《International Journal of Infrared and Millimeter Waves》1995,16(10):1811-1824
The radiation modes of a five-layered symmetric slab waveguide are treated in detail. Since the slab is assumed to be infinitely extended in the yz plane, all field quantities are considered to be independent of y. The analysis is based on modal expansion formulation and the modes can be classified as TE and TM as well as even and odd ones. Applying the boundary conditions at interfaces, the expansion coefficients of the field components are easily calculated. In addition, the normalization factors and the orthogonality properties are determined by deriving appropriate integrals over the cross section of the waveguide. Finally, the validity of the orthogonality relations between the radiation modes and the guided ones, which propagate in such a waveguide, is proved explicitly. 相似文献
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The propagation of an optical pulse in a coupled-resonator optical waveguide may be calculated nonperturbatively to all orders of dispersion, in the conventional tight-binding approximation, even though the dispersion relationship is nonlinear. Working in this framework, we discuss limits of the physical parameters and approximations to the exact formulation that highlight the conditions under which pulse distortion can be minimized. The results are fundamental to the design of coupled-resonator optical waveguides and are also relevant to other applications of the tight-binding method. 相似文献
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An exact solution of Maxwell's equations is found for TM-polarized nonlinear guided waves which are guided by a linear dielectric slab embedded between two nonlinear uniaxial media. Additional waves in comparison with the linear case arise. Some of these waves have no counterpart in linear systems. Similarities and differences with respect to TE-polarized nonlinear guided waves are pointed out. 相似文献
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We consider dispersion relations and field structure of TE-polarized guided waves travelling along an asymmetric dielectric slab surrounded by two different nonlinear media. For a given configuration there are four types of guided waves. Three of this four types possess at least one field maximum outside the slab region and have no counterpart in linear waveguide optics. The solutions of the dispersion relations depend now on an additional parameter making them more flexible with respect to the linear limit. 相似文献
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《Optics Communications》1987,64(1):31-35
We investigate how bulk losses of the thin film waveguide core influence the propagation constants of the modes of an asymmetric slab waveguide. Film absorption of a few hundreds inverse centimeters causes measurable shifts of the effective refractive indices, particularly for modes of higher order. We evaluate the error, that would be introduced into measurements of the refractive index and film thickness by the prism coupler method, if existing film losses were to be ignored. 相似文献
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D.J. Robbins 《Optics Communications》1983,47(5):309-312
A theory is presented of guided TE modes in a one-dimensional slabe waveguide bounded by nonlinear media with intensity dependent refractive indices. It is shown that this is a straightforward generalisation of linear slab waveguide theory with the modes parametrised by the power flow down the guide. Illustrative dispersion curves and mode shapes are discussed. 相似文献
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A. Azéma J. Botineau F. Gires A. Saïssy 《Applied Physics A: Materials Science & Processing》1979,19(2):145-147
A dielectric slab deposited on a conducting substrate can guide different types of electromagnetic modes. We present the study
of the lowest-order TM mode, which is a distortion of surface polaritons at the air/substrate and layer/substrate junctions. 相似文献
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We consider a nonlinear cylindrical fiber with a nematic liquid crystal (LC) core having initially the escaped configuration and subject to the action of a normal mode propagating electromagnetic field of arbitrary intensity. We derive a set of coupled equations governing the nonlinear dynamics of the electromagnetic field and the confined LC. We solve numerically these coupled equations and find simultaneously the distorted textures of the nematic inside the cylinder and the Transverse Magnetic modes in the guide. We analyze the dependence of these solutions on the electromagnetic field intensity by assuming consistently soft boundary conditions. We have found a dramatic correlation in the spatial distribution of the nematic's configuration and the Transverse Magnetic modes. Thus, the director adopts configurations completely guided by the specific mode involved. We show that the cut-off frequencies and dispersion relations can be tuned by varying the intensity of the electromagnetic propagating field. 相似文献
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Ewa Weinert-Raczka 《Optics Communications》1984,49(4):245-247
The theory of nonlinear interaction between two radiation modes as a pump waves and two guided modes: the input beam and the generated backward beam, is presented. In the degenerate case, for all waves at the same frequency, we demonstrate the possibility of the input wave amplification and the phase conjugate replica generation as well as of the interaction between modes of different polarization. The nondegenerate case, with the phase matching achieved by pump waves amplitude modulation is also considered. 相似文献
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The energy input and frequency shift of geodesic acoustic modes (GAMs) due to turbulence in tokamak edge plasmas are investigated in numerical two-fluid turbulence studies. Surprisingly, the turbulent GAM dispersion relation is qualitatively equivalent to the linear GAM dispersion but can have drastically enhanced group velocities. In up-down asymmetric geometry the energy input due to turbulent transport may favor the excitation of GAMs with one particular sign of the radial phase velocity relative to the magnetic drifts and may lead to pulsed GAM activity. 相似文献
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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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We study light localization at a phase-slip defect created by two semi-infinite mismatched identical arrays of coupled optical waveguides. We demonstrate that the nonlinear defect modes possess the specific properties of both nonlinear surface modes and discrete solitons. We analyze the stability of the localized modes and their generation in both linear and nonlinear regimes. 相似文献
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梯形截面脊形介质波导导模的分析 总被引:1,自引:1,他引:0
本文给出用分区分离变量法计算梯形截面脊形介质波导传插特性与场分布的近似方法.所导出的数学表达式形式简单,物理图象清晰,可用袖珍计算器进行计算,计算工作量较小,所得结果与精确数值计算结果符合较好. 相似文献