摘要：光子晶體是折射率不同的電介質材料周期性排列成的晶體結構。這種結構本身存在“禁帶”，也就是某些頻率范圍內的波不能在此周期性的結構中傳播。如果在光子晶體中引入線缺陷，那么原來在禁帶中的光就可以通過線缺陷傳播，這就形成了光子晶體波導。光子晶體中的各個波導之間會形成耦合。通過使用時域有限差分數值算法對二維光子晶體波導進行數值模擬，尋找出二維光子晶體中影響波導之間耦合效率的因素，然后我們就可以人為地控制波導耦合，可以增加波導間的耦合，也可以減弱耦合或無耦合。基于光子晶體波導耦合可以用來制作光分束器，光開關，波分復用器等。

關鍵詞： 光子晶體; 光子帶隙；波導耦合; 

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