含单负特异材料一维无序扰动周期结构中的光子局域特性研究  

Wave localization in one-dimensional periodic-on-average disordered system composed of single-negative metamaterials

作　　者：刘冬梅[1] 韩鹏[1] 

机构地区：[1]华南师范大学量子信息技术重点实验室,广州510006

出　　处：《物理学报》2010年第10期7066-7072,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10504008);教育部科学技术研究基金重点项目(批准号:209091)资助的课题~~

摘　　要：采用传输矩阵法研究了电磁波在由单负特异材料组成的一维无序扰动周期结构中的Anderson局域(Anderson Localization)行为,分别讨论了色散和非色散两种模型.结果发现,在对应周期结构的通带位置,无序的引入对局域长度的影响较大,而在带隙位置,影响较小,几乎可以忽略.该性质与我们曾讨论的随机结构有较明显不同.导致这种局域性质的主要原因应为,光在单负材料组成的系统中的传输主要依赖于两种单负材料间的界面.在无序扰动结构中,该界面数相对于周期结构并没有减少,因此对光的传输性质影响较小;而随机结构中,界面数显著减少,导致该结构中光被强烈局域,表现出相对较小的局域长度.在色散模型中,研究发现无序对于带隙中心的光的传输性质没有影响.特殊的,当两层的有效光程厚度比为1时,该处是一退局域点.这些结果有利于了解由特异材料组成的结构系统中光的传输机理。By using the transfer-matrix method,we study the Anderson localization behavior in one-dimensional periodic-onaverage disordered system composed of two different single-negative（SNG） metamaterials.Non-dispersive and dipersive models have been studied respectively.It was found that the disorder has great effect on waves with frequency in the pass band of the corresponding periodic structure.However,inside the gap,the effect can be almost ignored.These features are different from those we ever found in the random single-negative system.The main reason of the difference should be the number of the interfaces between two kinds of single negative metamateirals,which should be the basic mechanism of the wave propagation in systems made of single negative metamaterials.In periodic-on-average disordered systems,the number of the interface is the same as that in periodic one.However,there is an obvious decrease in random systems,which will have a great effect on the ability of wave transport,leading to small localization length.In the case of a dispersive model,it has been proved that the randomness has no effect on the wave propagation with frequency at the center of the gap.Especially,this special point becomes a delocalization point when the ratio of effective optical thickness of two single negative materials equals one.The results facilitates further understanding of the wave transport mechanism in systems composed of metamaterials.

关 键 词：单负特异材料 局域长度 传输矩阵法 退局域 

分 类 号：O436.3[机械工程—光学工程]