中文摘要：

采用平面波展开法(PWM)研究了基于三角晶格、复合蜂窝晶格和改进的复合蜂窝晶格光子晶体光纤(PCF)的包层中不同层气孔和掺杂介质柱尺寸对光纤带隙的影响.结果表明,在第m层(m=1,2,3)空气孔直径改变同样大小的情况下,随着m的增大,第m层空气孔尺寸的变化对带隙的影响越来越小;通过改进光纤结构中介质柱的排列,或掺杂折射率比较大的介质,可以有效地调节或增宽光子带隙(PBG),具有改进的复合蜂窝品格结构的光子晶体光纤可实现更宽的带隙分布.

英文摘要：

The influence of the air hole size of different rings and the doped dielectric cylinders size in the cladding on the band gap is investigated by plane-wave expansion method(PWM), for photonic crystal fibers(PCF) based on the triangular periodic structure, the composite honeycomb structure and the improved composite honeycomb structure. It is demonstrated that photonic crystal fiber band gap is most sensitive to the air hole size variation in the first two rings. When the change of the air hole size in the m-th ring is constant, the effect of the air hole size changing on the band gap decreases with the increasing of m. Through improving the arrangement of these dielectric cylinders in structure or doping the high refractive-index medium, the band gap can be regulated or made wider effectively. Compared with other two structures, photonic crystal fiber with improved composite honeycomb structure can achieve a wider band gap.