共查询到20条相似文献,搜索用时 437 毫秒
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本文提出一种新型函数光子晶体, 其折射率是空间位置函数. 由费马原理, 我们给出光在一维、 二维和三维函数光子晶体中的运动方程, 以及一维函数光子晶体的色散关系、 带隙结构和透射率, 再利用传输矩阵理论研究函数光子晶体周期数、 入射角和介质层的厚度等对透射率和禁带结构的影响, 计算发现通过选择不同的折射率空间分布函数, 可以得到比传统光子晶体更宽或更窄的禁带结构. 这样为我们设计不同带隙结构的光子晶体提供理论依据. 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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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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对于具有周期单元的分层介质材料高反射区的波长范围,提供一种简明的估计分析方法.基于Floquet定理,分析了有限周期单元分层介质的光子带隙特性,给出分层介质的高反射区波长范围.讨论了分层介质高反射区和周期单元禁带之间的关系.计算表明,高反射区和周期单元禁带的中心波长彼此一致.并且,随着分层介质周期单元数的增多,高反射区的深度和带宽就越接近于周期单元禁带的深度和宽度.最后,讨论周期分层介质的光子带隙特性与入射角及其与极化的变化关系.
关键词:
分层介质
带隙特性
周期单元
高反射区 相似文献
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与介质光子晶体相比,金属光子晶体的带隙特性在毫米波和亚毫米波波段有着重要的应用价值.基于Yee网格的频域有限差分法推导得出的本征模方程,求解后能方便而又可靠地得出介质光子晶体的带隙图和场分布.但由于金属与介质的本质差异,该方法不能直接应用于金属光子晶体.文中引入了金属表面边界条件,推导了二维金属周期结构的光子带隙本征模方程.通过数值计算,得出了不同晶格结构(正方/三角格子)下两种模式(TE/TM)的全禁带特性,并与介质周期结构的禁带特性进行对比,分析了金属周期结构在模式选择和器件集成方面的优点. 相似文献
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《中国光学与应用光学文摘》2005,(1)
O436 2005010070 光波在一维周期介质中传播的色散和反射=Dispersion and reflection properties of light in one-dimensional periodical media[刊,中]/王维江(中山大学光电材料与技术国家重点实验室,广东,广州(510275)),肖万能…∥光子学报.-2004,33(3).-366-370 从光的电磁理论出发,导出了光在一维周期介质中的特性矩阵的表达式。运用特性矩阵方法对光在周期介质 相似文献
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利用光学传输矩阵方法,模拟计算了由铁磁材料组成的一维光子晶体的光学传输特性.研究了能带结构随介质层厚度h(O ≤h≤0.5λ0 λ0=1.2×10-6m)变化的规律,并与相同周期结构的普通光子晶体的传输特性进行了比较.结果表明,当O.15λ0<h<0.165λ0时,铁磁光子晶体的带隙宽度略小于普通光子晶体的带隙宽度;在h取其他值时铁磁光子晶体的带隙宽度远远大于普通光子晶体的带隙宽度,并且在h=0.25λ0时存在最大值.这种结构的光子晶体通过掺杂有望在多通窄带滤波技术中得到广泛的应用. 相似文献
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Based on the transfer matrix method (TMM), the interaction of electromagnetic waves with one-dimensional (1D) defective photonic crystal in ultraviolet (UV) frequency region had been studied. With the calculated transmittance characteristics in the wavelength domain, it can be found that the defect mode can be generated within the photonic band gap (PBG) at the central wavelength. Also the effects of many parameters such as the angle of incidence, the state of polarization and the defect layer thickness have been taken in account. A significant effect in generating multiple defect peaks within the PBG has been illustrated. 相似文献
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Photonic bandgaps (PBGs) of two-dimensional (2D) triangular-lattice and square-lattice and decagonal quasi-periodic photonic crystals (PCs) have been analyzed, with a given scatterer radius and dielectric relative permittivity changing from 1 to 30 within air-cylinders-in-dielectric and dielectric-cylinders-in-air constructions. The results have shown that 2D quasi-periodic PC is more likely to generate PBG and complete PBG than 2D periodic PC. For the given scatterer radius and two constructions, PBG widths of the two types of 2D PCs vary little, whereas the corresponding center frequencies decrease in smooth “hyperbola-like” curves with dielectric relative permittivity increasing monotonically. The present results will guide the design of PBG-type microstructure photonic devices. 相似文献
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Band gaps of two-dimensional photonic crystal structure using conjugated polymer (3-octylthiophenes) 总被引:1,自引:0,他引:1
The possibility of using conjugated polymer (3-octylthiophenes, P3OT) as two-dimensional (2D) photonic band gap crystals was investigated. The different aspects were examined of the absolute photonic band gap (PBG) formation for 2D photonic crystals (PCs) consisting of P3OT pillars in air. The formation of PBG was exhibited and confirmed by a calculation of transfer matrix method (TMM). It was found that P3OT triangular structure could be good candidate for absolute inhibition of reflection in ultraviolet frequency region for given orientation. 相似文献
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Based on the non-symmetric transmission-line method, the band gap structure of disordered chiral photonic crystals (CPC) has
been investigated. The influence of the chiral parameters, the disorder, the periods and the refractive index on the band
gap structure has been discussed. It is found that the photonic band gap (PBG) in CPC is more obvious than that in the conventional
photonic crystals, and the PBG can be increased by increasing the periods or the contrast of the refractive index of the two
media. It is also found that the existence of disorder will influence the band edge of the PBG, and such influence will increase
with the increment of periods or the contrast of the refractive index of the two media. 相似文献
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研究了二维光子晶体量子阱的光谱特性,该量子阱结构由二维正方晶格圆柱晶胞光子晶体通过移去中间位置的介质圆柱层形成。由于光子晶体中的光子禁带充当了光子运动的势垒,类似于半导体量子阱中电子的行为,在光子晶体量子阱结构中会出现量子化的光子能态。文章利用平面波展开法计算了所用光子晶体的能带结构,利用传输矩阵方法计算了量子阱结构的透射光谱。计算结果表明,在光子禁带中出现了离散的透射峰,透射峰的强度随着势垒宽度的增加而减弱,个数随着势阱宽度的增加而增加,通过计算得到了其定量关系,并且讨论了透射峰频率与势阱宽度的关系。 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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Plasma Bragg grating (PBG) is composed of periodic variations of plasma and dielectric or vacuum. The defect mode characteristic of the PBG with a cavity-defect is studied by one-dimensional particle-in-cell (1D PIC) simulation. It is shown that the laser pulse with the defect frequency can be localized around the defect partly and at the same time leak out of both sides of the grating slowly because of the few number of the grating period. This results in local high laser field intensity and high plasma density produced at the defect area, from which the third harmonic is enhanced by one order of magnitude. With the enhancement of the light coupled to the defect and the decrease of the light leaking out of the defect, the conversion efficiency of the third harmonic from the incident laser can be increased. 相似文献
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Photonic amorphous diamond structure with a 3D photonic band gap 总被引:1,自引:0,他引:1
We report that a full three-dimensional (3D) photonic band gap (PBG) is formed in a photonic amorphous structure in spite of complete lack of lattice periodicity. It is numerically shown that the structure "photonic amorphous diamond" possesses a sizable 3D PBG (18% of the center frequency for Si-air dielectric contrast) and that it can confine light at a defect as strongly as conventional photonic crystals can. These findings present important new insight into the origin of 3D PBG formation and open new possibilities in developing 3D PBG materials. 相似文献
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We introduce the ‘decay rate' terms into the density matrix equations of an atom embedded in a photonic band gap (PBG) reservoir successfully. By utilizing the master equations, the probe absorption spectra and the refractivity properties of a three-level atom in the PBG reservoir are obtained. The interaction between the atom and the PBG reservoir as well as the effects of the quantum interference on the absorption of the atom has also been taken into account. It is interesting that two different types of the anomalous dispersion relations of refractivity are exhibited in one dispersion line. The methodology used here can be applied to theoretical investigation of quantum interference effects of other atomic models embedded in a PBG reservoir. 相似文献