结构无序对8重准晶光子晶体带隙特性的影响

采用时域有限差分法(FDTD)对介质柱构成的8重准晶光子晶体(PQC)的光子带隙(PBG)特性进行了研究,分别讨论了介质柱尺寸无序和位置无序对其带隙宽度、位置和各向同性的影响.数值模拟结果表明,随着介质柱尺寸无序和位置无序的增大,8重准晶光子晶体带隙的中心频率向低频方向移动,带隙的相对宽度均变窄,但介质柱尺寸无序对带隙的影响远大于位置无序的影响.当尺寸无序达到介质柱半径的一半时,带隙完全消失,而对于相同大小的位置无序,相对带隙宽度只改变了1%;同时,在较大结构无序范围内,带隙的各向同性也能很好地保持.

Effect of Structure Disorder on Band Gap of Eight-Fold Photonic Quasicrystals

The photonic band gap(PBG) of eight-fold photonic quasicrystal(PQC) with dielectric cylinder structure is studied using the finite difference time domain(FDTD) method,and the effect of disorder of cylinder size and displacement of cylinder sites on the width,site and anisotropy of photonic band gap is numerically investigated.When the disorder of cylinder size and displacement of cylinder sites increase,the central frequency of the photonic band gap has a redshift,and the relative band gap width decreases.The band gaps are much more sensitive to disorder of cylinder size than displacement of cylinder sites.When the disorder of cylinder size is half the cylinder radius,the band gap disappears completely,but the band gap only changes 1% for the same size of displacement of cylinder site.The isotropy of band gap is maintained in a large range of structure disorder.