应变对二维蜂巢晶格光子晶体能带结构的影响

基于平面波法,本论文对应变引起的二维蜂巢晶格光子晶体的能带结构进行了数值计算。选取的两个方向分别是锯齿型边界(zigzag)方向和扶手椅型边界(armchair)方向,在这两个典型方向上对二维蜂巢晶格进行了正负各20%的单轴应变。由于应变导致的对称性破缺,能带结构会有显著的变化。在沿锯齿型边界方向上,TE模带隙随着晶格被拉伸逐渐减小,TM模带隙在应变量大于16%时消失。对于沿扶手椅型边界方向,TE模带隙在压缩15%以上时逐渐减小,在其他应变量的情况下几乎保持不变;TM模带隙在应变量大于18%时消失。这些结果对于完善应力工程和设计二维光子晶体器件有重要的指导意义。

Impacts of the Strain on Band Structures of Two-Dimensional Photonic Honeycomb Lattices

Based on plane wave method,the impacts of strain on band structures of two-dimensional photonic crystal with honeycomb lattices are studied numerically in this work.The directions of strain are assumped to be along zigzag and armchair boundary,and the range of uniaxial deformation is 20%.The bandstructure change obviously since strain-induced symmetry breaking.For the strain along zigzag direction,the gap of TE mode decreases with the stretching of crystal lattice,while the gap of TM mode disappears when the strain is over 16%.As for the strain along armchair direction,the gap of TE mode gradually decreases when the compressed strength is over 15% and keeps almost rubust for other strain case;the gap of TM mode vanishes for a strain larger than 18%.These results play an important role in improving strain engineering and designing two-dimensional photonic devices.