结构参数对二维Archimedes A7晶格光子晶体禁带的影响

利用平面波展开法对空气背景中介质圆柱和方柱构造的二维Archimedes A7晶格光子晶体的禁带结构随介质折射率、填充比的变化关系进行了研究,并进一步计算了介质方柱的旋转角度对完全光子禁带宽度的影响.研究发现,介质圆柱构造的Archimedes A7晶格结构在介质柱折射率最低为n=2.40时出现完全光子禁带,当n=2.60时禁带宽度达到最大值.介质方柱构造的Archimedes A7晶格结构在介质柱折射率n=3.80时完全禁带宽度达到最大值,且随着折射率的增加禁带宽度变化很小;在介质方柱折射率恒定情况下,其最大禁带宽度与旋转角度无关,但旋转后出现完全禁带的填充比范围明显扩大.

Effect of structure parameters on the bandgap of two dimensional Archimedes A7 photonic crystals

Plane wave expansion method is introduced to simulate the band structures of two-dimensional photonic crystals made of Archimedes A7 lattice of circular and square dielectric rod in air. The bandgaps of Archimedes A7 lattice with dielectric rods is also discussed as the refractive index, filling fraction and rotation angle change. The results show that the complete bandgap can be obtained when the refractive index is greater than 2.40, the width of complete bandgap reaches the maximum when the dielectric refractive index of the circular rod is equal to 2.60. For the Archimedes A7 lattice of square dielectric rod, the complete bandgap reaches the maximum when the dielectric refractive index equals 3.80, and the maximum complete bandgap changes in a narrow range as the refractive index increases. When the rotation angle of square dielectric rods changes, the maximum bandgaps can be attained steadily as the refractive index is a constant, the filling fraction scope where the complete bandgap appears significantly expanded.