共查询到18条相似文献,搜索用时 203 毫秒
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基于横向磁光效应磁化等离子体光子晶体的光子带隙特性 总被引:2,自引:0,他引:2
通过外加与电磁波传播方向垂直的磁场来调控等离子体光子晶体的光子带隙结构。采用时域有限差分方法数值分析了由本征层为等离子体层和其他电介质材料层交替堆叠而成的磁化等离子体光子晶体的光子带隙结构和频谱特性。数值结果表明,光子晶体中等离子体的介电常数随着外磁场大小的变化而改变,从而使磁化等离子体光子晶体的带隙特性在一定的频率范围相应地得到调节。 相似文献
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两类单负材料组成的一维光子晶体的光学特性研究 总被引:3,自引:2,他引:1
从光的电磁理论出发,导出了光在单负材料周期性结构的传输矩阵:利用光学传输矩阵法对由两类单负材料组成的一维光子晶体的光学传输特性进行了数值模拟和理论分析:结果表明,这种结构具有一类新型的光子带隙。与布喇格带隙不同的是,这类光子带隙不会随着品格常数的缩放而移动。 相似文献
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利用传输矩阵法研究了正负折射率材料构成的异质结构光子晶体的光学传输特性。结果表明:当入射波正入射时,在这种异质结构光子晶体内出现了光子带隙,并且带隙内出现了3个极窄的透射峰,这是正负交替光子晶体和常规材料构成的同周期一维异质结构光子晶体所不具有的新颖物理特性。计算了这种异质结构光子晶体的透射谱。发现:这3个透射峰不敏感于入射角的变化,而在带隙两侧的透射峰则会随着入射角增大统一向带隙靠近;能带敏感于晶格厚度和周期数的变化。 相似文献
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理论研究了由级联一维光子晶体构成的光子异质结构的全方位透射(反射)特性.其中各级联光子晶体的高低折射率介质相同、光学厚度比不同.以两个光子晶体级联的结构为对象,利用传输矩阵方法系统研究了不同偏振态光在不同入射角时光子帯隙的变化,得出实现全方位光子带隙的最大展宽条件,即前一光子晶体的帯隙上限要和后一光子晶体的带隙下限在最大入射角时重合.分别给出了满足和不满足该最大展宽条件的级联结构的全方位带隙参量,通过对全方位带隙宽度的比较说明了满足最大展宽条件的级联结构具有最大的全方位带隙宽度. 相似文献
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一维光子晶体禁带的展宽 总被引:13,自引:6,他引:7
作为一维光子晶体的应用基础,一维光子晶体的禁带是研究的重点。通过传输矩阵的方法分析了一维光子晶体禁带的特性,讨论了影响带宽的因素。说明了相对带宽对光子晶体设计的重要性。在这个基础上讨论了扩展一维光子晶体带宽的方法,提出了在角域范围内对光子晶体进行叠加的方法,为设计制造一维光子晶体提供了一种行之有效的方法。分别对2个、3个和4个晶体的叠加进行了分析,最后计算了所设计的合成晶体的反射率。其中4个晶体的叠加,相对带宽达到57.52%,极大地展宽了一维光子晶体的禁带,从而证明利用角域的叠加来展宽一维光子晶体的禁带是非常有效的。 相似文献
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含负折射率材料的一维光子晶体的光学传输特性 总被引:12,自引:2,他引:10
采用光学传输矩阵方法,模拟研究了由正折射率材料和负折射率材料交替组成的一维光子晶体的光学传输特性.计算了这种含负折射率材料的一维光子晶体的透射谱和色散关系.结果表明,在正入射时,含负折射率材料的光子晶体的带隙要比传统的光子晶体要大得多,并具有狭窄的透射带,从光学薄膜理论的色散关系出发解释了形成上述现象的原因.讨论了在不同的偏振模式下,光以中心波长入射时,反射率随着入射角度的变化关系.发现含负折射率材料的一维光子晶体具有更好的角度特性,可以用来实现对中心波长的全方位反射. 相似文献
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利用转移矩阵方法对二维正方介质柱光子晶体的传输特性进行了研究,数值计算研究了不同晶格、同一晶格柱体截面面积不同、放置方位角不同时光子晶体的传输特性。数值结果表明光子禁带的宽度与中心频率和晶格结构有很大关系,正方晶格更易形成平坦光子禁带,柱体截面面积大,则形成的禁带较宽,在其他因素相同的条件下柱体放置的方位角对光子禁带有重要影响。数值研究表明在正方介质柱下设计宽平坦光子禁带时,可以首先考虑正方晶格结构,其次设法使柱体截面尽量大一些,最后可通过柱体放置方位角来微调光子禁带的宽度与中心频率以达到设计要求。 相似文献
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Xiang-kun Kong Shao-bin Liu Hai-feng Zhang He-lan Guan 《Optics Communications》2011,284(12):2915-2918
The electromagnetic properties of one-dimensional plasma photonic crystals influenced by random perturbation of structure parameters are studied through transfer matrix method in the paper. The random perturbation of thicknesses of layers as well as plasma frequency of layers can influence the electromagnetic properties of one-dimensional plasma photonic crystal. The random perturbation of thicknesses of layers tremendously impacts the band structure of one-dimensional plasma photonic crystals in high frequency domain. The random perturbation of plasma frequency, however, contributes to the moving of a cutoff frequency in the low frequency domain. The position of the defect mode of one-dimensional plasma photonic crystal randomly moves due to the random perturbations. The effect of random perturbation of plasma frequency is more significant than that of random perturbation of thickness of layers, which alters not only the transmittance but also the position of the defect mode. An improved quality factor and a shortened moving distance of the defect mode are both acquired by increasing the period number. And then this work may provide a crude but useful instrument in analyzing disordered 1DPPCs. 相似文献
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Band gap characteristics of plasma with periodically varying external magnetic field 总被引:1,自引:0,他引:1
The reflectance characteristics of a one-dimensional periodically magnetized plasma structure is studied by using the transfer matrix method. It is found that this system has the band gap characteristics of photonic crystals, so we also name it a plasma photonic crystal. The results show that the gap location and gap width can be controlled by the incident angle. If the external magnetic field is small, the gap location and gap width change significantly with incident angle, while they change only slightly when the external magnetic field is sufficiently large. The collision frequency has little effect on the gap location and gap width while it makes the amplitude of reflectance and transmission decrease. This new type of plasma photonic crystal could have potential applications in designing tunable photonic crystal devices. 相似文献
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The transmission properties of Fibonacci quasi-periodic one-dimensional photonic crystals (1DPCs) containing superconducting material are theoretically investigated based on the transfer matrix method. It is shown that the 1DPCs can possess a same photonic band gap property as the periodic structure superconducting PC. The results of transmittance spectra show that the cutoff frequency can be manipulated through the thicknesses of the superconductor and dielectric layers as well as the ambient temperature of the system. It is observed that the shift of cutoff frequency becomes more noticeable by adjusting the thickness of the superconductor layer than that of the dielectric one. Furthermore, the cutoff frequency becomes very sensitive when the system temperature is tuned to close vicinity of the critical temperature of the superconductor. 相似文献
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Laxmi Shiveshwari 《Optik》2011,122(17):1523-1526
We consider the oblique propagation of electromagnetic waves in one-dimensional plasma dielectric photonic crystals, the superlattice structure consisting of alternating plasma and dielectric materials using transfer matrix method. Our results show that photonic band gaps for all polarizations can be obtained in one-dimensional plasma dielectric photonic crystals. These structures can exhibit a new type of band or gap, for the incidence angles other than normal incidence, near frequencies where the electric permittivity of the plasma layer changes sign. This new band or gap arises, from the dispersive properties of the plasma layer, only for TM polarized waves and its width increases with the increasing angle of incidence. This differential behaviour under polarization can be utilized in the design of an efficient polarization splitter. The band characteristic is affected by the plasma width, the plasma density, dielectric width, the dielectric constant of the dielectric medium and angle of incidence. 相似文献