共查询到20条相似文献,搜索用时 109 毫秒
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以砷化镓圆形介质柱在空气中构成二维六边形排列结构的光子晶体为例,利用时域有限差分法模拟研究了光子晶体表面结构改变对负折射透射光强的影响.模拟结果表明:针对同一结构光子晶体,在可产生负折射现象的入射光频率范围,改变光子晶体表面两侧圆形介质柱的半径和顺向侧移两侧表面最外层圆形介质柱都会均对负折射透射光强产生影响. 相似文献
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以砷化镓圆形介质柱在空气中构成二维六边形排列结构的光子晶体为例,利用时域有限差分法模拟研究了光子晶体表面结构改变对负折射透射光强的影响.模拟结果表明:针对同一结构光子晶体,在可产生负折射现象的入射光频率范围,改变光子晶体表面两侧圆形介质柱的半径和顺向侧移两侧表面最外层圆形介质柱都会均对负折射透射光强产生影响. 相似文献
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本文研究了硅柱在MnFe2O4磁性液体背景中排列成六边形结构的二维光子晶体的可调谐负折射特性. 利用平面波展开法和时域有限差分法理论研究了硅柱-磁性液体体系二维光子晶体的带隙结构、等频曲线和负折射现象随外磁场强度的变化关系. 模拟结果表明, 硅柱-磁性液体体系二维光子晶体工作在TE模式时, 其负折射特性可由外磁场调节. 在固定背景溶液的磁性颗粒体积分数和入射光频率时, 所研究的折射光束的偏转角和光子晶体的负折射率绝对值随外磁场的增大而增大, 而在固定背景溶液的磁性颗粒体积分数和外磁场强度时, 负折射角和负折射率的绝对值随入射光归一化频率增大而减小. 固定外场强度和入射光频率时, 所研究结构的负折射特性随背景溶液的磁性颗粒体积分数增大而变弱. 相似文献
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波状结构二维光子晶体近场亚波长成像的研究 总被引:7,自引:5,他引:2
研究了波状结构二维光子晶体(2DPC)在红外波段的负折射近场成像,对其等频面进行了分析,指出波状结构二维光子晶体无法实现负折射远场成像的原因在于缺少与入射介质等频面相匹配的光子晶体圆形等频面,所用的矩形等频面使波状膜层二维光子晶体不可避免地具有各向异性特征,进而将成像限制在近场范围内。采用时域有限差分(时域有限差分)方法模拟了不同厚度的波状结构二维光子晶体近场成像效果,当厚度为两倍栅格常量时,单光源的成像分辨力为0.28λ,达到亚波长分辨效果。分辨力随着光源逐渐远离近场范围而降低,而像点的位置基本不随光源距离和光子晶体厚度的变化而改变。双光源的成像模拟进一步验证了波状结构二维光子晶体的近场亚波长成像能力,分辨力达到0.35λ,但成像质量受光子晶体厚度变化的影响较大。 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由空气环组成的二维三角晶格光子晶体平板的负折射成像特性.研究结果表明对于外半径为 0.4 a,内半径 0—0.13a的空气环型光子晶体,第二能带中归一化频率为 0.3 的电磁波可以实现有效折射率为-1的负折射成像.通过光子晶体有效折射率的计算,得到了有效折射率为-1的电磁波频率随空气环内径由0—0.2 a变化的规律,并由对应等频曲线的变化解释了结构参数对光子晶体平板成像的影响.
关键词:
光子晶体
空气环
负折射
等频曲线 相似文献
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Although the investigation on photonic band gap materials has been done more than two decades, it is still a big challenge to fabricate three-dimensional photonic crystal (PC) possessing wide band gaps in visible range. In this article, we have reviewed recent progresses on fabricating the PC with low refractive index material in visible range. In contrast to the material with large refractive index, it is cheap to use low refractive index material in fabricating the PC and will be greatly beneficial for future industrial productions. The holographic method to fabricate such a PC has been introduced, applying it to the design of the microlaser has also been discussed. 相似文献
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Although the investigation on photonic band gap materials has been done more than two decades, it is still a big challenge
to fabricate three-dimensional photonic crystal (PC) possessing wide band gaps in visible range. In this article, we have
reviewed recent progresses on fabricating the PC with low refractive index material in visible range. In contrast to the material
with large refractive index, it is cheap to use low refractive index material in fabricating the PC and will be greatly beneficial
for future industrial productions. The holographic method to fabricate such a PC has been introduced, applying it to the design
of the microlaser has also been discussed. 相似文献
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One-dimensional photonic crystals (1DPCs) composed of dispersive materials (including negative refractive index materials, negative μ materials, and negative ? materials) are proposed. The dependence of the band gaps on the angle of incidence and thickness scale are investigated by using the transfer matrix method. Simulation results show that the band gaps of these dispersive material 1DPC are insensitive to the thickness scale. The defect modes of these doped 1DPCs behave specially when the thickness of the defect layer, the angle of incidence and the thickness scale of PC change. 相似文献
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The effects of the defect and doping on the transmission properties are investigated in two-dimensional photonic crystal (PC) with triangular rods using the finite difference time domain (FDTD) method. The results show that the width and the central position of the photonic band gap (PBG) depend on the thickness of rods with defect or composite-defect, and the refractive index of doped dielectric rods. The transmission properties of composite-defect combined with doping are further investigated. The thinner the nested concentric triangular rod and the smaller the refractive index is, the wider the band gaps is. 相似文献
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利用传输矩阵法研究了异质双周期结构一维光子晶体的带隙结构和光学传输特性。此光子晶体能形成512~960 nm的含5个极窄透射峰的光子带隙。重点研究了一种材料为复折射率时的光学传输特性,以及当结构发生轴向应变时的"介观压光效应"。结果表明:当复折射率虚部为负时,透射峰随虚部绝对值的增大先增大后减小,甚至出现衰减;虚部为正时,发生吸收现象。当光子晶体发生轴向应变时,透射峰随应变量的增加呈现近似L形变化,应变量很小时透射率几乎线性减小,波长越大透射峰变化越缓慢。 相似文献
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含负折射率缺陷的一维光子晶体的杂质带 总被引:1,自引:1,他引:0
利用传输矩阵方法研究了含负折射率缺陷的一维光子晶体的透射谱.以19个周期的1/4波堆存在3个负折射率缺陷的光子晶体为例进行了数值计算.结果表明:如果改变缺陷的折射率,缺陷模之间的耦合作用将发生改变,带隙中形成的杂质带也随之改变; 当这个折射率取适当值时,在禁带中出现多个尖锐的透射峰,与正折射率缺陷构成的杂质带不同. 相似文献