摘要：光子晶体是折射率不同的电介质材料周期性排列成的晶体结构。这种结构本身存在“禁带”，也就是某些频率范围内的波不能在此周期性的结构中传播。如果在光子晶体中引入线缺陷，那么原来在禁带中的光就可以通过线缺陷传播，这就形成了光子晶体波导。光子晶体中的各个波导之间会形成耦合。通过使用时域有限差分数值算法对二维光子晶体波导进行数值模拟，寻找出二维光子晶体中影响波导之间耦合效率的因素，然后我们就可以人为地控制波导耦合，可以增加波导间的耦合，也可以减弱耦合或无耦合。基于光子晶体波导耦合可以用来制作光分束器，光开关，波分复用器等。

关键词： 光子晶体; 光子带隙；波导耦合; 

Abstract：Photonic crystal is a crystal structure arranged by the different refractive index dielectric material  periodically. This structure itself exists "forbidden band", Certain waves within the frequency scope can't propagate. If we construct a line defect in the photonic crystal, the light in the original forbidden bandgap can propagate along the line defect. Photonic crystal waveguide could couple with each other. Through FDTD numerical study and numerical simulation of two-dimensional photonic crystal waveguide, we can find out the factors which affect the waveguide coupling efficiency in two-dimensional photonic crystal. Then we can artificially control the waveguide coupling, we can increase the coupling, or decrease the coupling as well as eliminating the coupling. Based on photonic crystal waveguide coupling, we can design and fabricate beam splitters, optical switches, WDM and so on.

Key words: photonic crystal; photonic crystal bandgap; waveguide coupling