共查询到20条相似文献,搜索用时 171 毫秒
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《光子学报》2015,(8)
采用传输矩阵法分别模拟了缺陷层厚度、入射角度和膜厚微扰的变化对含空气缺陷的一维光子晶体滤波特性的影响.研究表明:对于空气厚度可调结构,在考虑色散的情况下,空气厚度每增加2nm透射波长相应向长波方向移动约2nm,二者基本呈1∶1的线性关系;对于入射角度可调结构,与正入射相比较,入射角度从0°到89°变化时,其全角度禁带分别减小了105nm(TE模)、600nm(TM模),TM模禁带受角度的变化影响较大;入射角从0°分别变化到16.9°(TE模)、17.0°(TM模)时实现C波段的可调滤波.同一周期内,两种材料的模厚误差的相互弥补,能够实现小范围的膜厚扰动不敏感,缩小实际滤过峰值与理论值的偏差,可降低制备光子晶体的难度. 相似文献
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基于传输矩阵法,设计多层一维光子晶体,改变层数和入射角度,应用MATLAB语言进行仿真计算,得到入射角度为0.2rad时,8、16、24层和32层一维光子晶体在[9.77-23.39]THz频范围内存在一个低传输率的传输禁带,只是在两侧的低频和高频部分Fabry-Perot峰变得越来越紧密.改变入射角度为0.1rad、0.2rad和0.3rad时,在低频带范围Fabry-Perot峰变化不大,传输禁带依次增大,高频带部分逐渐压缩.研究结论为一维光子晶体传输器件的设计提供参考. 相似文献
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二维光子晶体中的无序数值模拟研究 总被引:13,自引:0,他引:13
应用on-shell方法研究弱无序情况下的二维光子晶体,无序的引入使得原来不透电磁波的禁带中,出现了共振模,即某一波长的电磁波可以透过,计算结果表明共振模的出现位置,条数多少及透过率随着无序程度的不同而变化。 相似文献
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在一维线缺陷的研究基础上进一步应用转移矩阵方法数值研究带其它缺陷的二维正方晶格圆柱光子晶体的透射谱,缺陷的引入使得原来不透电磁波的禁带中,出现了缺陷模,即某一波长的电磁波可以透过,计算结果表明禁带位置、宽度,缺陷模的位置与透过率随着缺陷的种类、介质、程度有关,特别是都受到波源的入射角调制. 相似文献
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采用时域有限差分法研究了二维八重准晶有机光子晶体的光传输特性,重点分析了光束在聚苯乙烯空气柱平板结构和聚苯乙烯介质柱结构中的透射特性与光局域特性。研究结果表明,即使在低折射率对比度的情况下,两种完整八重准晶平板结构中均出现了可见光波段的光子带隙和本征模,且光子带隙中心位置随着平板厚度的增大而红移。当在两种准晶结构中引入缺陷微腔时,带隙内的缺陷模产生位置和波长红移特性随着微腔结构的变化规律明显不同,这种差异性是由两种物理机制(即光子晶体缺陷能级变化与微腔所支持的驻波条件)共同作用的结果。这一研究结果将为实验制备有机准晶发光器件提供一定的理论基础。 相似文献
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最近研究表明,两束交叉激光脉冲在等离子体中传播时,可以诱导生成周期等离子体密度调制(或称等离子体布拉格光栅). 分别利用传输矩阵法和耦合模理论,推导了激光斜入射时等离子体光栅的色散关系. 两种方法均表明,均匀等离子体光栅存在着光子带隙结构,并且在带隙附近有强烈的色散. 当激光斜入射时,带隙结构会呈现不同的偏振特性:S偏振光的带隙宽度随着入射角的增大而逐渐变宽,而P偏振光的带隙宽度随着入射角的增大先迅速变窄,在布儒斯特角入射时带隙消失,然后又随着入射角的增大而迅速变宽. 超宽的光子带隙和超高的激光损伤阈值,使得等离子体光栅有望成为一种新型的操纵强激光脉冲的光子器件.
关键词:
等离子体光栅
传输矩阵法
耦合模理论
光子带隙 相似文献
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本文基于Bragg反射光栅是一维光子晶体的一种特例结构, 提出利用一维光子晶体理论进行Bragg衍射光栅的设计并对其性能进行研究分析. 根据一维光子晶体理论, 建立了罗兰圆结构的凹面椭圆Bragg蚀刻衍射光栅, 研究了TE/TM模式下器件的分光特性以及入射角度改变对器件角色散造成的影响; 同时, 文中对比了空气介质型和金属铝线型椭圆Bragg蚀刻衍射光栅的光学性能. 研究结果表明: 选择合适的器件参数, 可以实现TE/TM模式下1.465-1.615 μm范围内波长衍射效率在95% 以上, 且空气介质型结构光栅的通道均匀性要优于金属铝线型结构光栅; 入射角在30°-60°范围内变化时, 相同入射角度下, TM模式下器件角色散大于TE模式. 基于Bragg衍射光栅设计的波分复用器是一种尺寸小、衍射效率高的新型EDG 波分复用器, 为未来密集型EDG波分复用器发展提供了一种新的设计思路. 相似文献
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Y. T. Fang Z. C. Liang 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,61(3):725-729
The reflection phase difference between TE and TM waves
in one-dimensional photonic crystals composed of single-negative (SNG)
(permittivity- or permeability-negative) materials is investigated by
transfer matrix method. Within two omni-directional gaps the reflection
phase difference changes smoothly and increases with the increasing of the
incident angle. In the center of the second omni-directional gap the
reflection phase difference remains almost unchanged in a broad frequency
band. Especially, at both the edges of the second omni-directional gap the
reflection phase difference keeps zero in spite of the change of incident
angle. Based on these properties, a continuously tunable phase compensators
and an omni-directionally synchronous reflector for TE and TM waves can be
designed. The working frequencies for the phase compensators and synchronous
reflector are tunable. 相似文献
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采用平面波展开法和时域有限差分法研究了二维色散和各向异性磁化等离子体光子晶体的色散特性.当波矢在周期平面时,由于外加磁场的作用使TE模的色散曲线出现两个不同区域的平带,改变磁场的大小不但可以控制平带的位置,而且可以控制光子带隙的位置和大小.增大背景材料的介电常数,可以形成全方向光子带隙,随着背景材料介电常数的增加,带隙的中心位置降低但带隙宽度增加.当波矢偏离周期平面时,色散曲线不再分为TE和TM模,随着非周期平面波矢的增加,带隙位置上移,带隙宽度先增加随后基本保持不变. 相似文献
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Shao-Wei Wang Wei Lu Xiao-Shuang Chen Mei Zhou Xue-Chu Shen 《International Journal of Infrared and Millimeter Waves》2003,24(6):963-971
Photonic band gap (PBG) in two-dimensional (2D) anisotropic photonic crystal (PC) constructed of rectangular bars has been numerically studied by using Transfer Matrix Method (TMM). The results show that the PBG is bounded by the lower band edge of TE wave and the upper band edge of TM wave. Its width simply increases with increasing of shape parameter . It reaches a maximum value as the structure degenerates into its 1D counterpart, due to the complete overlapping of gaps in TE and TM waves. The anisotropy in PC structure results in the transmission anisotropic property. One can design the PBG structures in different incident directions to match their application demand. 相似文献
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提出了一种具有完全带隙的二维复式晶格光子晶体,该晶体是在二维正方形格子中,旋转截面为正方形的柱子,同时在每个原胞中心引入圆形截面的柱子而形成的,并在其中引入点缺陷。运用平面波展开法并结合超晶胞理论分析此缺陷态光子晶体的频率特性。仿真结果表明,通过调节缺陷的尺寸、角度等结构参量,可以改变缺陷态频率的位置,使TE和TM模缺陷态频率一致,TE模和TM模同时谐振,处于缺陷态频率的入射光就能够完全耦合进点缺陷,具有较高的耦合效率。这种结构的复式晶格完全带隙光子晶体为制作完全带隙光子晶体谐振腔提供了理论基础。 相似文献
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F. Xi L. Hu 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2012,66(2):33
We investigate the properties of electromagnetic wave propagating in a one-dimensional photonic crystal (PC) consisting of
two metamaterials with different dispersive model. The reflection gaps of metamaterials multilayer system are independent
of the incident angle. Not only TE wave but also TM wave, the omnidirectional reflection gaps exhibit the same behavior with
different incident angle for metamaterials as double negative material. We also observed that the frequency regimes of zero-transmission
bands are different for TE and TM wave with the same incident angle, when one of metamaterials is the permittivity negative
(ε < 0) and the other is the double negative. Correspondingly, we show that the result can be act as an efficient polarization
splitter. At last, we discuss the resonant tunneling effect. If the total reflection condition is satisfied, the resonant
tunneling effect is enhanced as the incident angle increases, even though the propagation wave is evanescent wave in the single
layer medium. 相似文献
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Complete photonic band gaps (PBGs) are found in one-dimensional ternary photonic crystals (1D TPCs) composed of an ordinary dielectric and single negative metamaterials. The proposed TPC gives omni directional PBG completely independent of polarizations dependent weekly on angle of incidence. Here the choice of different parameters of TPC is done in such a way so that it eliminates the Brewster's-angle transmission resonance, thus allowing a complete 3D PBG. It exhibits a photonic band or gap near frequencies where either the magnetic permeability or the electric permittivity of the metamaterial changes sign, whose width increases with the increasing angle of incidence. These result from the dispersive properties of the metamaterials and disappear for the particular case of propagation along the stratification direction. The results are discussed in terms of incident angle, layer thickness, dielectric constant of the dielectric material for TE and TM polarizations. 相似文献