共查询到20条相似文献,搜索用时 46 毫秒
1.
Y. T. Fang Z. C. Liang 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,61(3):725-729
The reflection phase difference between TE and TM waves
in one-dimensional photonic crystals composed of single-negative (SNG)
(permittivity- or permeability-negative) materials is investigated by
transfer matrix method. Within two omni-directional gaps the reflection
phase difference changes smoothly and increases with the increasing of the
incident angle. In the center of the second omni-directional gap the
reflection phase difference remains almost unchanged in a broad frequency
band. Especially, at both the edges of the second omni-directional gap the
reflection phase difference keeps zero in spite of the change of incident
angle. Based on these properties, a continuously tunable phase compensators
and an omni-directionally synchronous reflector for TE and TM waves can be
designed. The working frequencies for the phase compensators and synchronous
reflector are tunable. 相似文献
2.
3.
采用角域叠加方法可以有效地获得可见光区域的一维光子晶体全角度反射器. 4个TiO2 /SiO2薄膜光子晶体用角域叠加形成全角度反射的相对带宽为4133%, 而在同样条 件下用常规的频域叠加方法合成的全角度反射的相对带宽仅为1426%. 阐述了角域叠加的 基本原理,计算给出了可见光区域的全角度反射器,并提出用角域叠加方法可方便地构建频 域叠加所无法实现的紫外区域的全角度反射器.
关键词:
薄膜光子晶体
可见光区域
全角度反射器
角域叠加方法 相似文献
4.
一维光子晶体禁带的展宽 总被引:7,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
5.
研究了不同尺寸SiO2胶体微球形成纳米结构薄膜的光学传输特性和光子带隙。通过在玻璃基底上自组装透光的SiO2胶体微球形成胶体晶体薄膜, 依据布拉格定律,分析微球尺寸对胶体晶体光子带隙的影响。为实现可见光波段的全方位减反射,提出通过改变胶体粒径将胶体晶体带隙位置移动至紫外波段,理论计算得出当粒径为112 nm,占空比为0.45时能实现可见光波段0.5%的平均反射率。实验结果表明,玻璃基底在400~800 nm间的平均反射率从4.3%降低至0.7%,最小反射率达0.3%。通过控制微球粒径移动光子带隙位置,优化晶体结构参数实现了可见光波段的减反射,有效提高了光学组件对可见光的利用率。 相似文献
6.
In this paper the omni-directional reflection bands in one-dimensional plasma photonic crystal (PPC) have been studied theoretically. We present the study of plasma photonic crystal, having alternate regions of plasma?dielectric (Al2O3 or ZnS). Reflectances from this periodic multilayered structure in TE- and TM-modes are calculated for different angles of incidence in microwave region for omni-directional reflection bands. The reflectance is obtained by solving a Maxwell's equation using a translational matrix method. In addition to this, we have also studied the effect of variation of plasma width as well as plasma density on the reflection properties of plasma dielectric photonic crystal in TE- and TM-modes. The study of reflectance bands of such plasma photonic crystals shows that it can be used as omni-directional reflector. 相似文献
7.
光子晶体的禁带特性为伪装材料的光谱控制研究提供了一条新的技术途径。利用传输矩阵的方法建立了一维光子晶体光谱透射、反射的理论模型,针对伪装材料近红外高反射、中远红外低发射的要求,优选Ag,MgF2和ZnS等材料作为光子晶体的薄膜材料,采用真空蒸发镀膜的方法制备出Ag/MgF2,Ag/MgF2/ZnS 4种不同周期结构的一维光子晶体,并实验研究了一维光子晶体的光谱反射和透过特性。结果表明:材料和周期结构对一维光子晶体光谱特性有不同的影响,通过优化设计可以实现在伪装波段内的光谱特性要求。 相似文献
8.
9.
连续渐变周期的一维光子带隙结构全能反射器 总被引:20,自引:7,他引:13
采用转移矩阵法设计了一种具有连续渐变周期的一维光子带隙结构全能反射器,它在一般材料选取情况下(如TiO2/SiO2),在可见光区能达到几十甚至几百纳米量级的带隙宽度全向反射.研究表明,其带隙宽度随着周期数和渐变周期的大小改变而改变.当周期数不断增大时,带隙宽度不断增大;当渐变周期的大小在一定范围内不断增大时,带隙宽度同样不断增大.这主要是光波在各层之间的传播随着周期和渐变周期的大小不断增大而产生的相干散射和干涉效应不断增强所导致的. 相似文献
10.
11.
12.
Zhong Yin Xiao Zi Hua Wang 《International Journal of Infrared and Millimeter Waves》2004,25(9):1309-1314
In this paper, a novel chiral photonic crystal structure is presented. The formula of reflection coefficient of multi-layer chiral media is applied to dielectric-chiral photonic crystal structure, which is composed of thin chiral layers sandwiched by conventional media. To compare with previous literature, we consider the dielectric structure with alternate glass and GaAs layers. The power reflectance as a function of wavelength for this photonic crystal structure has been calculated. The results are in good agreement with that of Reference. However, our method is simpler. From these graphs, it is found that 100% reflectance is only in finite wavelength ranges, and reflection bandwidth is also small for conventional photonic crystal structure. For chiral photonic crystal, the results show that the chiral photonic band gap (PBG) structure gives nearly 100% reflections in the near-infrared region in addition to some parts of the visible region of the wavelengths. Therefore, it can be used as a broadband reflector and filter. 相似文献
13.
一维金属/介质光子晶体用于BaF2晶体闪烁光谱修饰 总被引:14,自引:6,他引:8
利用一维金属/介质光子晶体对BaF2晶体闪烁光谱进行修饰. 以Al2O3/MgF2/Al/ MgF2为周期构成光子晶体,讨论了周期数、金属层的厚度以及在低折射率层中的相对位置、入射角度等与光子晶体能带特性的关系及其对BaF2晶体闪烁光谱进行修饰的效果. 结果表明,在所考虑的发射角范围,光子晶体对快成分的衰减小于5倍,对慢成分的相对抑制比超过20倍,采用合适的探测角度,可使对慢成分的相对抑制比提高到100以上. 相似文献
14.
利用等离子体辅助分子束外延设备(P-MBE)在m面的蓝宝石(m-Al2O3)衬底上制备了ZnO/Zn0.85Mg0.15O多量子阱.反射式高能电子衍射谱(RHEED)图样的原位观察表明,多量子阱结构是以二维模式生长的.从光致发光谱中可以看到ZnO/Zn0.85Mg0.15O多量子阱在室温仍具有明显的量子限域效应.在290 K时阱宽为3 nm的ZnO/Zn0.85
关键词:
等离子体辅助分子束外延
ZnO多量子阱
光致发光 相似文献
15.
16.
17.
紫外区全角度光子晶体反射镜 总被引:3,自引:3,他引:0
根据角域叠加原理,在石英玻璃基板上用全介质膜系实现了紫外区域全角度一维光子晶体反射镜的设计。采用两个不存在全角度反射带的一维光子晶体在角域上叠加,通过传输矩阵方法,从理论上计算合成光子存在全角度禁带,禁带波长范围328.95~352.11nm,相对带宽为6.80%。实验上采用HfO2和SiO2两种薄膜材料,用电子束蒸发的方法在石英玻璃基板上制备合成光子晶体。若透射率在1%以下为光子晶体禁带,则禁带波长范围从331.2~350.4nm,相对带宽5.63%。从而证明了角域叠加设计的正确性。 相似文献
18.
色散SiO2/TiO2薄膜组成的Fibonacci序列一维光子晶体在可见光波段的传输特性 总被引:1,自引:0,他引:1
用特征矩阵法研究了由正常色散SiO2/TiO2薄膜组成的Fibonacci序列一维光子晶体在可见光波段的传输特性,并与无色散时的传输特性做了对比。结果表明,随序列项数的增加,相应的前一序列的透射谱中透射率较低的凹带逐渐变成禁带,禁带数增加;初始介质是低折射率的SiO2薄膜时比高折射率的TiO2薄膜时各序列的透射谱中的禁带数多,各禁带的宽度和中心波长基本相同;在总厚度一定的条件下,随SiO2薄膜的厚度增大(TiO2薄膜的厚度减小),禁带的宽度减小,禁带的中心波长基本不变;随入射角增大,禁带的中心波长向短波方向移动,禁带宽度变小。在其它相同条件下,无色散时的最宽禁带和最宽禁带的中心波长比有色散时的最宽禁带和最宽禁带的中心波长都有增加。 相似文献
19.
In this communication dispersion relation, reflection and transmission coefficient for quasiperiodic optical multilayers arranged according to the three-component Fibonacci rule is derived using transfer matrix method. In this work Fibonacci multilayers using three different photonic band gap (PBG) materials is designed and its photonic band gap structure is presented. Also, a detailed calculation for allowed and forbidden frequency bands for s-polarized radiation of light incident on these structures at various angles is presented. It is demonstrated that in case of s-polarized mode of radiation, widening in the band gap and frequency shifts occur as one moves towards the higher frequency region, which shows that such a multilayer can be used as an efficient polarizer. The effect of an imaginary value for the propagation vector Q on the existence of forbidden photonic bands in these lattices is also studied. 相似文献
20.
为了在可见及近红外波段得到具有良好带隙结构的三维光子晶体,利用传输矩阵法分析了MgF2、Ta2O5 以及Ta2O5/MgF2异质结构三维光子晶体的带隙性质.结果表明:Ta2O5/MgF2异质结构三维光子晶体在820~1 020 nm的近红外波段TM模式下具有不受入射光方向影响的全方位光子带隙.该结构有望用于制作近红外光波段的偏振器件. 相似文献