基于方形孔线缺陷的新型光子晶体零色散慢光结构研究

Investigation on a Novel Photonic Crystal Structure with Dispersion-Free Slow Light Based on Line-Defect of Quadrate Air Holes

为了获得最优化的光子晶体零色散慢光结构,在传统的光子晶体线缺陷波导结构的基础上,进一步在线缺陷上下两侧各引入了两排方形空气孔,并进一步优化了这两排方形孔的结构参数。通过平面波展开法(PWE)与时域有限差分法(FDTD)进行数值分析表明,这种新型结构的光子晶体波导能够在中心波长1550 nm处实现带宽为8.34 nm、平均群折射率为61、群速度色散(GVD)为104量级的理想宽带慢光。

To obtain the optimized structure of photonic crystals with dispersion-free slow light,based on the traditional line-defect structure of photonic crystal waveguides,we introduce a novel type of slow light photonic crystal waveguide with a line defect which is surrounded by four rows of quadrate air holes,and optimize the structural parameters of the two rows of quadrate air holes.By means of the plane wave expansion（PWE） and 2D finite difference time domain（FDTD）,our numerical analysis shows that,at the center wavelength of 1550 nm,our new design can present a wideband dispersion-free slow light,which in possession of a wavelength bandwidth of 8.34 nm,an average group index of 61 and a group velosity dispersion（GVD） of 104.