同质位错缺陷二维声子晶体带隙结构及传导模的研究

为了研究声子晶体因缺陷而产生的声波导问题,提出了同质位错缺陷模型.以二维铝圆柱/空气体系正方格子声子晶体为研究对象,采用平面波法结合超元胞的方法研究了声子晶体同质位错结的传导模.结果表明,横向位错效应与线缺陷相似,它可以使处于禁带频率范围内的声波沿位错通道进行传播,形成声波导;纵向位错效应由于其对称性而类似于点缺陷,界面两边3个最接近的"格子"形成腔,因而能够产生局域模.横向位错距离和纵向位错距离的大小将影响传导模的位置和数量.

Study on band gaps structure and transmitting mode of 2-D homogeneous dislocation defect photonic crystal

A homogeneous dislocation defect model was established to study the sonic waveguide of a photonic crystal with defects.The transmitting mode of the homogeneous dislocation junction of the photonic crystal,which is composed of two dimensional aluminum cylinders and a square lattice of air was studied with the plane-wave and super cell method.The results indicate that the transverse dislocation effect can make the sonic wave in the range of the gap frequencies transport along the dislocation channel and then make the photonic crystal a sonic waveguide similar to the line defects.Also,the longitudinal effect can produce the local mode because the three nearest "lattices" to both sides of the boundary make a channel for the symmetry of the longitudinal effect that is similar to that of the point defect.The magnitude of the transverse and longitudinal dislocations can have effect on the location and amount of the transmitting mode.