共查询到20条相似文献,搜索用时 46 毫秒
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在对周期性结构进行谐波分析的基础上,导出了非截面二维光子晶体排列矩形波导的本征值方程. 基于此方程,可以对该类光子晶体波导的所有可能模式进行分析. 分析认为,非截面二维光子晶体排列矩形波导内能存在的模式包括E(y),TEy,H(y)和TMy模式;改变波导高度,可以实现E(y)模式和H(y)模式与其他模式通带的完全分离. 然而改变任一结构参数,都不能使E(y)和H(y)的各个模式通带,以及E(y)1模式和H(y)1模式的通带完全隔离. 波导单模工作的带宽由E(y)1和E(y)2模式的低端截止频率决定.
关键词:
波导
光子晶体
本征值方程
模式 相似文献
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采用科尔-霍普夫(Cole-Hopf)变换法,将渐变折射率波导导模的本征值方程变换为里卡提(Riccati)方程,通过较简洁的数学演算导出导模的传播常量与模场分布的解析解,给出了平方律分布、对称爱泼斯坦(Epstein)分布、爱泼斯坦层的平板波导与平方律分布圆光纤4种折射率分布的计算公式。 相似文献
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基于等几何分析方法具有自由度花费少、高精度、高阶连续性等特点,通过加权余量法对椭圆波导本征问题的亥姆霍兹方程等几何离散得出等几何分析方程.解决了传统数值方法的求解域与几何模型的非一致性问题,实现了将问题的分析计算构架于精确几何模型基础之上.分析任意截面波导的本征问题,对不同偏心率的椭圆波导以及三角形和五边形波导的截止波数的求解结果显示等几何分析方法求解波导本征问题的高效及高精度特性.与传统方法相比,此方法以较少的自由度消耗便会达到较高的求解精度,并且数值解的收敛率较快. 相似文献
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求复折射率波导本征值的打靶法 总被引:1,自引:2,他引:1
给出了求一维缓变复折射率波导本征值的打靶法,它是对求一维实折射率波导本征值的打靶法的推广,利用它可以分析增益或损耗对TE和TM模式的影响,并给出了计算实例。 相似文献
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The characteristics of electromagnetic waves in a narrowing waveguide are investigated. A method for field analysis is developed based on the application of transverse modes parametrically dependent on the longitudinal coordinate. For a circular cross section waveguide, a system of equations for the wave amplitudes is obtained, the waves being coupled owing to a variable tilt of the walls. It is shown that in the adiabatic approximation, there exist independent eigenwaves whose structure reflects the field energy density variation due to the waveguide radius variation. A detailed analytical and numerical investigation of these fields has been carried out for a waveguide with a special profile of hypergeometric type. The applicability of the adiabatic approximation is studied and conversion of the fundamental mode into higher-order modes is assessed. The amplitudes of the higher-order modes are obtained using the Green function for ordinary differential equations. The region of the waveguide parameters is found where the higher-order mode amplitudes are not great and the adiabatic approximation is highly accurate. The dependence of the transmittance of a semi-infinite waveguide on the input radiation characteristics is obtained. It is established that the field amplitudes at the waveguide output strongly depend on the wavelength of the input radiation, on its transverse structure, and the waveguide profile steepness. The greatest output fields take place in the case of an abrupt dependence of the waveguide radius on the longitudinal coordinate. 相似文献
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以电磁场理论为出发点,对满足环状截面同轴金属波导边界条件的麦克斯韦方程组求解,得到了环状同轴波导管内的电磁场各分量方程,并以TE模灰例详尽分析了环状金属波导管中的模式特征、色散关系、光束传播及其强度分布特性。 相似文献
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This paper investigates the dynamics of two two-level atoms, which simultaneously couple to a quasi-1D waveguide with rectangular cross section. The waveguide modes serve as environment, which induces the interaction and collective dissipation between the two distant atoms. When both of the two atoms are located in the middle of the waveguide, a retardation effect is observed, which can be broken by moving one of the atoms away from the center of the waveguide. To preserve the complete dissipation of the system via dark state mechanism, a scheme where the connection of the atoms is perpendicular to the axis of the waveguide is proposed. 相似文献
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We study a quantum electrodynamics(QED) system made of a two-level atom and a semi-infinite rectangular waveguide, which behaves as a perfect mirror in one end. The spatial dependence of the atomic spontaneous emission has been included in the coupling strength relevant to the eigenmodes of the waveguide. The role of retardation is studied for the atomic transition frequency far away from the cutoff frequencies. The atom-mirror distance introduces different phases and retardation times into the dynamics of the atom interacting resonantly with the corresponding transverse modes. It is found that the upper state population decreases from its initial as long as the atom-mirror distance does not vanish, and is lowered and lowered when more and more transverse modes are resonant with the atom. The atomic spontaneous emission can be either suppressed or enhanced by adjusting the atomic location for short retardation time.There are partial revivals and collapses due to the photon reabsorbed and re-emitted by the atom for long retardation time. 相似文献
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有机聚合物非对称脊波导单模条件分析 总被引:2,自引:1,他引:1
以有机聚合物非对称脊波导为研究对象,采用半矢量有限差分光束传输法(FD-BPM),系统地分析了不同脊高、脊宽和芯层平板短侧宽度条件下非对称脊形波导的基模截止和单模条件。得出:在芯层高度一定的情况下,基模截止区域和单模区域均随脊高或脊宽的缩小而增大,单模区域随脊形波导芯层平板短侧宽度s的减小而减小;其尺寸以选择芯层厚度h≥1.5μm,脊高(H-h)≤0.4μm,脊宽4μm≤w≤8μm,芯层平板短侧宽度s=2μm较佳。研究表明,非对称脊波导单模条件区域仍能满足实际应用要求。 相似文献
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Analysis for Transmission Characteristics of Closed Trapezoidal-Groove Waveguide with Boundary Element Method 总被引:1,自引:0,他引:1
Fuyong Xu Xiaohui Lin Bin You 《International Journal of Infrared and Millimeter Waves》1999,20(9):1691-1699
In this paper, the cut-off and dispersion characteristics of a new kind of closed trapezoidal-groove waveguide that has more advantages than open groove waveguides are analyzed with the help of the boundary element method, the relationship between cut-off wavelengths and variations of guide's relative sizes is discussed in detail. The calculated results are in good agreement with those in the relevant reference. So, the obtained conclusions are very important in theoretical studies and actual applications of closed trapezoidal-groove waveguides for millimeter and submillimeter waves. 相似文献