共查询到18条相似文献,搜索用时 531 毫秒
1.
基于含单负材料光量子阱结构的全向多通道滤波器 总被引:1,自引:1,他引:0
分析了含单负材料的光量子阱结构中的振荡透射模的性质.用两种单负(负介电常量或负磁导率)材料交替周期堆叠形成的两个光子晶体构造了一维光量子阱结构,该结构中仅其中一个光子晶体含有零有效位相带隙.数值计算结果发现,在零有效位相带隙内存在振荡透射模.通过改变井区域光子晶体内单负材料层的厚度及周期数,振荡透射模的数目、频率及频率间隔均可调节.振荡透射模对入射角度的依赖均很弱;随着入射角度的改变,缺陷模频率的相对改变量保持在0.02以下.该研究结果可用于设计多通道全向滤波器. 相似文献
2.
多个单负材料缺陷一维光子晶体的孪生缺陷模 总被引:4,自引:0,他引:4
分析了含有多个单负材料缺陷层的一维光子晶体中缺陷模的性质。在两种单负(负介电常量或负磁导率)材料交替堆叠形成的一维光子晶体中,掺入了多个周期排列的单负材料缺陷层,得到在该光子晶体的零有效相位(zero-effective phase)带隙内存在孪生缺陷模。通过改变缺陷的数目或缺陷层的厚度,可调节缺陷模的频率间隔,但缺陷模的数目总保持为两个。计算结果显示,该孪生缺陷模的频率对入射角度的依赖较弱;随着入射角度的改变,缺陷模频率的相对改变量总保持在0.03以下。此外,对应缺陷模频率的电场在该光子晶体中传播时,将被强烈地局域在缺陷层与周期结构的交界面上。 相似文献
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构造了(AB)N(BA)N对称型两种单负材料交替一维光子晶体,利用传输矩阵法进行数值模拟.结果表明:这种单负交替对称型一维光子晶体具有一种特殊带隙结构,该带隙不敏感于入射角和晶格的无序性.在该带隙内出现了两个隧穿模,该隧穿模不敏感于入射角的改变和晶格的无序性,但能带及带隙内的隧穿模却敏感于晶格标度和周期数的变化;随着入射角的改变,带隙两侧的隧穿模趋于简并.这些特性对在利用此结构光子晶体设计双重超窄带滤波器时,具有一定的参考价值.
关键词:
光子晶体
单负材料
光子带隙 相似文献
4.
电负媒质和磁负媒质组成的一维光子晶体中存在一种几乎不受电磁波入射角和极化影响的零相位能隙.为了能够调节这种能隙的频率,通过在此类光子晶体中心插入一层各向异性媒介,构造出两层电负扣磁负媒质交替的一维光子晶体.采用Berreman 4×4矩阵法计算了该结构的透射谱,结果显示:调节双轴晶体主轴围绕实验坐标系z轴的旋转角度可以改变缺陷模频率的大小,并且该缺陷模的频率不随入射角度的变化而改变.该特性可以用于光波频率可调的单通道窄带滤波器的制作. 相似文献
5.
两类单负材料组成的一维半无限光子晶体反射谱 总被引:1,自引:1,他引:0
运用传输矩阵方法和Bloch定理计算了两类单负材料组成的一维半无限光子晶体反射谱,与有限多层结构通带中振荡的反射谱相比,半无限结构的反射谱曲线是光滑的,是有限周期结构反射谱振幅取平均的结果,可用来估计通带中的反射率.研究半无限结构的反射谱,有利于分析带隙的位置和宽度,结果表明,由两类单负材料组成的光子晶体中,不仅存在零有效位相带隙,还存在角度带隙,尤其发现高频处的Bragg带隙也是一个全方位带隙. 相似文献
6.
用传输矩阵方法研究了由两种单负材料构成的光子晶体异质结构的透射特性.结果表明,当异质结构具有零有效折射率时,由于迅衰场表面模共振耦合,在异质结构双周期光子晶体的每一个分界面上都会出现隧穿模.零有效折射率隧穿模不受入射角、电磁波偏振态、结构周期数和晶格常数标度等因素影响,并且具有零相位延迟,这一特性可用来设计零相位延迟全向多通道滤波器件.而位于中心两侧的隧穿模随入射角、结构周期数和晶格常数标度的减小都统一由中心向两侧移动.
关键词:
单负材料
异质结构
传输矩阵 相似文献
7.
通过传输矩阵方法, 计算模拟了两种单负材料组成一维光子晶体双量子阱结构的透射谱. 研究发现: 由于双量子阱结构双阱之间的相互耦合作用, 共振模发生双重劈裂, 共振峰之间的距离可以通过调节双阱之间的耦合强度控制, 共振模的品质因子可以通过调节外部障碍光子晶体的周期数控制. 并且, 共振模受入射角和光偏振模式的影响都比较小, 适合全方向滤波. 当考虑两种单负材料不同损耗的影响时, 研究结果表明, 电损耗对低频处的共振模影响大, 而磁损耗对高频和低频处的共振模影响都比较大. 相似文献
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利用传输线技术制备了左手材料,将左手材料与正常材料交替排列组合成平均折射率为零的一维光子晶体.该光子晶体在特定频段具有光子带隙,带隙不随晶格尺度和入射角的变化而改变.通过掺杂技术破坏光子晶体的周期性,可在禁带中引入缺陷模,这种结构的光子晶体可用于实现滤波器小型化和超强耦合.研究表明,通过调节缺陷的厚度可以控制缺陷模的频率,这为调节频率提供了一种方法.实验与仿真结果相符.
关键词:
左手材料
复合左右手传输线
光子晶体 相似文献
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The symmetrical confined states are found in photonic quantum-well structures with single-negative materials, in which the photonic barrier is based on the zero-effective-phase gap. The number and frequencies of the symmetrical confined states can be tuned by varying the period number and thicknesses of the well photonic crystal, respectively. Furthermore, the symmetrical confined states of the structures are less sensitive to the incident angle and polarization, compared with previous confined states of photonic quantum-well structures based on the Bragg or zero-average-index gap. The structures open a promising way to fabricate symmetrically tunable and omnidirectional multichannel filters for future dense wavelength division multiplexing applications. 相似文献
12.
Omnidirectional and independently tunable defect modes in fractal photonic crystals containing single-negative materials 总被引:1,自引:0,他引:1
Y. H. Chen 《Applied physics. B, Lasers and optics》2009,95(4):757-761
The properties and applications of omnidirectional and independently tunable defect modes in fractal photonic crystals containing
single-negative materials are demonstrated. The proposed fractal structures can produce as many defect modes as desired by
adjusting its structural parameters. The interaction effect between the defect states of such fractal structures is avoided,
so the frequency of each defect mode can be tuned independently. Furthermore, these defect modes inside the zero effective-phase
gap are insensitive to the incident angle. With perfect transmission, mode controllability and omnidirectional compatibility,
these structures open a promising way for designing omnidirectional multichannel filters with specific channels. 相似文献
13.
A type of photonic multiple quantum well (PMQWs) structure made of two different photonic crystals (PCs) with two kinds of single-negative materials is investigated. It is demonstrated by transfer matrix method that omnidirectional resonance modes are generated. The number of the resonance modes can be controlled by adjusting the periodic structure of the constituents. The resonance tunneling modes are weak dependence on incident angle and the scaling of the barrier photonic crystals. When the losses are taken into account, the effects of the losses coming from ENG media and MNG media on the resonance modes are striking difference. 相似文献
14.
The properties of photonic band gap in one-dimensional photonic crystals composed of single-negative metamaterials are studied theoretically. Our study shows that the photonic gap will vanish at a certain incident angle when both the phase-match and impedance-match conditions are satisfied simultaneously, suggesting that the bandwidth and location of the photonic gap are strongly dependent on the incident angle and polarization. However, the photonic gap will not vanish and may become insensitive to the incident angle when the two match conditions cannot be met. Our study also shows that losses in metamaterials have little effect on the properties of the photonic gap. 相似文献
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The properties of photonic quantum-well structures containing negative-index materials are studied theoretically, showing features remarkably better than conventional photonic quantum-well structures. Owning to the zero- gap of one-dimensional photonic crystals containing negative-index materials, the photonic quantum-well structures can be proposed as a multiple channeled filter which is very weak dependent on incident angle and polarization, and insensitive to the thickness disorder of the barrier photonic crystals. 相似文献
17.
In this paper, we theoretically study the propagation of electromagnetic waves in one-dimensional double-period quasi-regular structures consisting of negative-permittivity and negative-permeability metamaterials. A Drude-type dispersive response for both permittivity and permeability of single-negative metamaterials is considered. From the numerical results performed by transfer matrix method and effective medium theory, it is found that double-period photonic crystals can exhibit an omnidirectional gap at given microwave frequency. Such an omnidirectional gap is insensitive to incident angle and polarization, and is invariant upon the change of scale length. It is also found that this gap exists in all double-period sequences, and it is independent of structure sequence. Moreover, electromagnetic field distributions in this structures show that the fields are localized at each interface of two media. These results can lead to further applications of quasi-regular structures. 相似文献