光子晶体器件在高密度集成光通信中有广泛的应用，为解决光子晶体波导出射光场的空间控制，采用时域有限差分法分析光子晶体波导结构的缺陷传播特性，提出基于点缺陷优化波导结构，通过在波导出射口两侧加上点缺陷，出射光方向性有显著提高，实现三点光源干涉系统的光集束。模拟结果表明缺陷态越靠近能带结构中央，共振腔的耦合效率越高；相反，缺陷态越靠近能带结构边缘位置，则共振腔耦合效率越低，因此，选取禁带区域四分之一处对应的点缺陷，可以有效实现波导出射的光集束。

Photonic crystal devices in high density integrated optical communication have been widely used. In order to solve space control of the photonic crystal waveguide emitting light beaming, using the method of finite-difference time-domain, the defect waveguide propagation characteristics of photonic crystal waveguide structure are analyzed. Based on optimization of waveguide structure with point defects, through both sides with point defects in the waveguide, the emitting light direction is significantly improved, and the beaming of three-point light interference system is realized. The simulation results show that when the defect state is close to the central band structure, the coupling efficiency of the resonant cavity is higher, when the defect state is close to edge position of the band structure, the coupling efficiency of the resonant cavity is lower, therefore, the selection of point defect in the band 1/4 region can effectively realize the waveguide beaming.