光在有缺陷存在的斐波那契准晶中的透射特性

Wave Transmission Property in Fibonacci Quasi-lattice with Defects

利用传输矩阵方法,模拟研究了FC(N)准晶链排列的多层介质膜中存在不同缺陷情形时,光在其中传播的透射规律。结果表明,当Fibonacci准晶中存在缺陷时,引入了缺陷模,而且其缺陷模具有与自身结构相关的特点。还进一步模拟研究了存在负折射率吸收缺陷媒质时的FC(N)准晶链的透射系数,出现了共振透射率大于1的情形。同时还研究了负折射率缺陷媒质的虚部对禁带中共振透射峰大小的影响,发现并不是所有引入负折射率吸收缺陷媒质的准晶都会出现共振透射率大于1的现象。

Negative materials （with negative refraction ） are the oddity electromagnetism materials, very recently, Pendry proposed a revolutionary concept of ＂perfect lens＂： with the perfect lens,not only the phase of propagating waves but also the amplitude of evanescent waves from a near-field object could be restored at its image. The Fibonacci quasi-lattice have abundance content and simple structure. The optical transmission in an one-dimension Fibonacci quasi-lattice with different defects is investigated by means of the transfer-matrix method. When some defects are introduced into the Fibonacci quasi-lattice, a number of defect modes appear in the stop band. It is found that the transmission is different from that of the one-dimensional photonic crystal; for example, the doped mode＇s transmission coefficient doesn＇t reduce when the defects situation departure from the bosom and the doped mode＇s transmission coefficient is not the biggest when the optical thickness of defects is as the one-dimensional photonic crystal. And the introduced defects are the negative materials with absorb. Because of the special properties of the negative materials, it is seemed to introduce an active impurity materials in Fibonacci quasi-lattice, the photon density of state is increased, which increases the doped mode＇s transmission coefficient in the stop band very much and even more than one. We also compare the Fibonacci quasi-lattice consisting of fight handed materials with which of consisting of right-handed and left-handed materials with negative defect materials, the result shows that the negative mate- rials is useful to increase the band-gap width. And we also studied the effect to the doped mode＇s transmission coefficient from the image of the negative materials and found that the different extinction coefficient made different character： when the extinction coefficient is about 0. 1, the doped mode＇s transmission coefficient is near to 300, but when the extinction coefficient is bigger than 0. 5, the doped mode＇s transmission coefficient is almost disappear.