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阐述了完全光子禁带的概念.用光学特征矩阵方法,通过数值模拟计算,讨论了一维光子晶体出现完全光子禁带与晶体结构和介质材料的折射率的密切关系.具体计算了用同样两种介质材料组成3种不同结构的一维光子晶体,对于TM及TE电磁模式在不同入射角下的透射率谱,从中找出它们的完全光子禁带,发现3种结构的完全光子禁带的波长范围及宽度各不相同.另外,研究结果表明组成光子晶体的两种材料的折射率差别越大,两种电磁模的禁带越宽,越容易产生完全光子禁带.简单讨论了完全光子禁带出现的条件. 相似文献
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本文利用传输矩阵理论对掺杂的一维三元光子晶体的光学传输特性进行了研究。选取(ABC)5D1(CBA)5型的光子晶体模型,数值模拟结果表明,禁带内出现了多个透射率较高的透射带。随着缺陷层折射率的增加,透射率下降。基元几何厚度的增加会使缺陷模向长波方向平移,但缺陷层的几何厚度不影响缺陷模的位置。 相似文献
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利用遗传算法和传输矩阵法计算一维光子晶体能带结构,将一维光子晶体用像素填充法进行二进制编码模拟,结果找到全方位相对禁带宽度达42.54%的4层结构和43.75%的2层结构;给出了一维光子晶体4层最佳结构的能带图、20个原胞的反射率透射率频谱图.发现一维2层光子晶体的全方位禁带宽度对每层厚度的变化是不敏感的,但是随着两种介质折射率差的增大而增大. 相似文献
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负折射率材料是一种新型的人工合成材料,它的介电常数和磁导率都为负值。把负折射率材料和光子晶体相结合形成的负折射率光子晶体具有奇特的光电磁特性。用传输矩阵法计算光经过一维含负折射率光子晶体的透射情况,总结一维含负折射率光子晶体的光学特性,并简单介绍负折射光子晶体的应用前景。 相似文献
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通过从理论上分析介质层厚度、不同介质材料的折射率差及周期数对一维光子晶体红外发射率的影响规律,设计得到了可实现8~14μm波段低红外发射率性能的Ge/ZnS一维光子晶体。随后采用光学镀膜技术在石英基片上通过交替沉积Ge层和ZnS层的方法制得所设计的一维光子晶体,并采用扫描电镜(SEM)及傅里叶变换红外光谱(FTIR)分别对其微结构及光谱发射率进行了系统研究。结果表明,所制备一维光子晶体在8~14μm波段具有低红外发射率性能,其平均发射率可低至0.195。采用Ge、ZnS等无机半导体材料,通过合理的一维光子晶体设计同样可以获得低至0.2以下的红外发射率。 相似文献
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为了研究弹性波在固-液结构声子晶体中的能带特性,推导出了弹性渡斜入射固-液结构声子晶体的转移矩阵.利用它计算了固-液结构声子晶体中弹性波的透射系数.结果表明,当介质的分层厚度固定时,在透射渡中出现了多级禁带,禁带的频率中心随入射角的增加而向高频方向移动.当入射角固定时,禁带的频率宽度随介质的分层厚度近似呈反比变化,禁带的频率中心也随介质的分层厚度近似呈反比变化. 相似文献
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Hai-Feng Zhang Shao-Bin Liu Xiang-Kun Kong Bo-Rui Bian Ben Ma 《Journal of Superconductivity and Novel Magnetism》2013,26(1):77-85
In this paper, the properties of the omnidirectional photonic bandgap (OBG) realized by one-dimensional (1D) photonic crystals with a staggered structure which is composed of superconductor and isotropic dielectric have been theoretically investigated by the transfer matrix method (TMM). From the numerical results, it has been shown that such OBG is insensitive to the incident angle and the polarization of electromagnetic wave (EM wave), and the frequency range and central frequency of OBG can be tuned by the ambient temperature of system, the average thickness of superconductor layer, the average thickness of dielectric layer, and staggered parameters, respectively. The bandwidth of OBG can be notably enlarged with increasing average thickness and staggered parameter of superconductor layer. Moreover, the frequency range of OBG can be narrowed with increasing the average thickness, staggered parameter of dielectric layer, and ambient temperature, respectively. The damping coefficient of superconductor layer has no effect on the bandwidth of OBG under low-temperature conditions. It is shown that 1D superconductor–dielectric photonic crystals (SDPCs) have a superior feature in the enhancement of frequency range of OBG. This kind of OBG has potential applications in filters, microcavities, and fibers, etc. 相似文献
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Theoretical analysis of dye-sensitized solar cell integrated with photonic crystals based on coupled coherent and geometrical optics formalism has presented. The effect of structural parameters, such as thickness of layer, number of unit cells and light incident angle on the optical properties and photo-current magnification for the proposed photonic crystal based dye-sensitized solar cell have studied. The angular response of the cell in terms of light harvesting efficiency and cumulative photo-generation rate has also analysed. A strategy has presented to enhance the performance of the cell under oblique incidence. The effect of number of photonic crystal unit cells has also analysed in view of percentage enhancement in cumulative photo-generation rate. This work provides new insight into the design and tailoring of the photonic crystals to enhance the light harvesting efficiency in the solar cells. 相似文献
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《Advanced Powder Technology》2022,33(6):103594
A defect mode in the bandgap of photonic crystals is a key factor for potential applications, emission, bandpass filter, sensor, and low throughput laser. A Fabry-Perot type cavity was known as a multilayer film with a planar defect or a one-dimensional colloidal photonic crystal film with a planar defect. In this work, we have developed a simple and easy method by two colloidal crystals, i.e., face center cubic (fcc) structure, films bonded together by hot pressing to form a sandwich structure, and clear defect mode was observed in the photonic bandgap of fcc (1 1 1) direction. We have investigated the effect of the thickness of the defect layer in the sandwich structure on the optical properties. A single or double dips appeared in Bragg's diffraction peak at different planar defect thicknesses. In addition, a simulation of the reflection spectra of multilayer film calculation showed the defect mode is much influenced by the planar defect thickness. 相似文献
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Arafa H. Aly Doaa Mohamed Hussein A. Elsayed Dhasarathan Vigneswaran 《Journal of Superconductivity and Novel Magnetism》2018,31(11):3453-3457
Based on the fundamentals of the characteristic matrix method, we theoretically investigate the optical properties of onedimensional superconductor metamaterial photonic crystals. The photonic crystals are composed of a superconductor layer and two semiconductor metamaterial layers of In0.53Ga0.47As with different doping densities. The numerical results show negative values in permittivity of the metamaterial layer along a broad band of the incident radiation. The negative values show a significant effect on the optical properties of the present structure. Moreover, the optical properties of our design can be controlled by different parameters such as thicknesses of the layers, the operating temperature and the doping density. Our results may be suitable for different applications in the optical community. 相似文献
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Responsive photonic crystals have been developed for chemical sensing using the variation of optical properties due to interaction with their environment. Photonic crystals with tunability in the visible or near-infrared region are of interest for controlling and processing light for active components of display, sensory or telecommunication devices. Here, we report a hydrophobic block-hydrophilic polyelectrolyte block polymer that forms a simple one-dimensional periodic lamellar structure. This results in a responsive photonic crystal that can be tuned via swelling of the hydrophilic layers by contact with a fluid reservoir. The glassy hydrophobic layer forces expansion of the hydrophilic layer along the layer normal, yielding extremely large optical tunability through changes in both layer thickness and index of refraction. Polyelectrolyte polymers are known to be highly responsive to a range of stimuli. We show very large reversible optical changes due to variation of the salt concentration of a water reservoir. These one-dimensional Bragg stacks reflect incident light from the ultraviolet-visible region to the near-infrared region (lambda(peak)=350-1,600 nm) with over a 575% change in the position of the stop band. Our work demonstrates the extremely high responsivity possible for polyelectrolyte-based photonic materials. 相似文献
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Abstract Based on the transfer matrix theory, general conditions of polarization-independent transmissions in one-dimensional photonic crystals are derived. It is shown that the polarization-independent transmissions are obtained in photonic crystals consisting of two alternating layers with the same refraction index and optical thickness as well as the mutually reciprocal wave impedance. By using two different photonic crystals satisfying the above relation to constitute the light quantum-well structures, the structures have polarization-independent transmission properties. When a defective layer with wave impedance of 1 is introduced in the photonic crystals, the defective photonic crystals also have the polarization-independent transmission properties. In addition, polarization-independent low-pass spatial filters are achieved based on these photonic crystal structures. 相似文献
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A. H. Gevorgyan 《Technical Physics Letters》2006,32(8):698-702
The properties of defect modes in chiral photonic crystals with anisotropic defects are considered. The problem has been solved using the modified method of Ambartsumyan layer addition. The influence of the defect layer thickness and the optical axis orientation on the properties of defect modes is analyzed. At a certain thickness of the defect layer, the medium loses its main property, namely, the polarization dependence of diffraction reflection. 相似文献
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Hadi Rahimi 《Journal of Superconductivity and Novel Magnetism》2016,29(7):1767-1772
In the ultraviolet region and by using transfer matrix method, the transmission spectra of electromagnetic waves through one-dimensional quasiperiodic photonic structures consisting of high-temperature yttrium barium copper oxide (Y123) superconductor and strontium titanate (STO) dielectric layers are studied theoretically. It is shown that for TE polarization at oblique incidence two band gaps are created, while for TM polarization three band gaps are produced. The edges of both polarizations shift to higher wavelengths by increasing incident angles. Also, for angles of incidence greater than 78°, the second gap for TM-polarized light is eliminated. It is also found that in the supposed structure the number of PBGs can be modulated by the thickness of dielectric layer, while it is nearly insensitive to the thickness of superconductor layer. Interestingly, for the incidence angles other than normal incidence the structure can exhibit some narrow resonant peaks near wavelengths where the electric permittivity of the superconductor layer changes sign. These resonant peaks are only for TM polarization and not present for TE polarization. This structure can act as a very compact polarization sensitive splitters and defect-free multichannel narrowband tunable filters. 相似文献
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Ehab Abdel-Rahman Amr Shaarawi 《Journal of Materials Science: Materials in Electronics》2009,20(Z1):153-158
The properties of one-dimensional periodic and quasiperiodic photonic crystals with a defect layer have been investigated.
Transfer matrix method (TMM) has been used throughout this study. For periodic photonic crystals, results demonstrate the
independence of the defect mode frequency on the defect layer while the defect mode transmission coefficient varies with the
position of the defect layer position. On the other hand, defect mode frequency is not that responsive to the index of refraction
of the defect layer. The quality factor of the defect mode has been studied as a function of the defect layer position as
well as its thickness. For quasiperiodic photonic crystals, the frequency of the defect mode is very sensitive to the defect
layer position as well as its thickness. An enhancement of the quality factor of the defect mode has been observed. This study
may be valuable in designing optical devices and it may also provide a more accurate method to measure the index of refraction. 相似文献