根据傅里叶光学原理,研究了二维Thue-Morse准周期光子晶体结构的格点形状对其远场衍射特性的影响。通过对二维Thue-Morse准周期光子晶体远场衍射图案的分析表明,格点形状对低阶结构的衍射光场有明显影响,但不改变高阶结构的衍射光场分布,仅衍射精细结构的光强度有细微差别。为了证实数值模拟的结果,采用电子束刻蚀技术在聚甲基丙烯酸甲酯(PMMA)基底上制作了纳米量级的圆形空气孔和方形空气孔的二维Thue-Morse型准周期光子晶体,对其远场衍射的光学特性进行了实验观测,实验结果与理论模拟一致。
According to the principle of Fourier optics, the effect of the lattice shape of two-dimensional Thue-Morse quasicrystals (2D TM QC) on the diffraction patterns is analyzed. The shapes of lattices have a considerable influence on the diffraction pattern of the lower order 2D TM QC, but do not affect that of the higher order 2D TM QC, excepting a little change on the intensity distribution. And the above numerical results are demonstrated by the diffraction experiments of samples of 2D TM QC with the circle and square lattices, which are fabricated on the substrate of Poly Methyl Methacrylate (PMMA) by the Electron Beam Lithography (EBL). It is shown that the experimental results are consistent with the theoretic simulations very well.