二维硅薄膜光子晶体波导的设计及制作

为了制作可用于通信波段的二维硅光子晶体波导,研究了光子晶体波导的设计方法及制作工艺。应用平面波展开法计算了两种空气孔型光子晶体结构的TE波禁带,经筛选采用了三角晶格空气孔结构。同样利用平面波展开法计算了引入缺陷后二维三角晶格空气孔型光子晶体波导结构的TE波禁带,经对比发现归一化频率为0.295 7的缺陷态最适宜用来制备光子晶体波导,并据此设计了用于1.55μm波长的二维三角晶格空气孔型光子晶体波导,其晶格周期为458nm,空气孔直径为339 nm。对设计的结构参数进行了容差计算,结果表明误差在-3.95~5.65 nm方能满足设计要求。最后使用聚焦离子束刻蚀工艺,制作了所设计的波导结构,并进行了测试。测试结果表明,样品实际晶格周期为463nm,空气孔直径为344 nm,比设计值大5 nm,在容差允许范围内,满足设计要求。

Design and fabrication of two-dimensional photonic crystal waveguides on silicon films

In order to fabricate two-dimensional photonic crystal waveguides on silicon films, the design method and fabrication techniques were investigated. Firstly, the TE bands of the two-dimensional square lattice and triangular lattice air hole structures were calculated by using the plane wave expansion method,and the two-dimensional triangular lattice air hole structure was chosen. Then, by adding a line defect,the photonic band gaps of the two-dimensional triangular lattice were calculated also by using the plane wave expansion method. The reasonable photonic band gap whose normalized frequency was 0.295 7 was chosen, and the structure parameters of two dimensional photonic crystal waveguides used in the 1.55 μm were designed as the period of the lattice in 458 nm and the diameter of the air hole in 339 nm.Furthermore,the tolerances of structure paremeters were calculated as -3.95-5.65 nm. Finally, the photonic crystal waveguides were fabricated by using the focused ion beam etching. The testing shows that the period of the lattice is 463 nm, and the diameter of the hole is 344 nm, which are 5 nm larger than the design values,but still in the tolererce range.