太赫兹波技术和光子晶体技术相结合为设计太赫兹波功能器件提供了新的思路和方法.本文提出了一种基于二维光子晶体的双波长太赫兹波功分器.在光子晶体中引入由三个相互平行的单模波导形成的定向耦合型分束器和Y型结构的1×2型分束器，同时，在Y型结构的分支处分别引入两个介质柱.利用平面波展开法和定向耦合原理计算了在不同入射波频率下，耦合波导的耦合长度，并采用时域有限差分法对功分器的传输特性进行了模拟仿真分析.结果表明，在频率f1=1.0 THz时，实现了端口1和端口2的能量均分输出；在频率f2=0.893 THz时，通过非对称改变两个介质柱的折射率，可以实现端口3和端口4输出能量的自由分配.

The combination of photonic crystal technology and THz technology provides a new approach to design novel THz wave functional devices. A dual-wavelength THz power splitter based on two-dimensional photonic crystals was proposed. A directional coupler was formed by introducing three parallel single mode waveguides, and a 1×2 Y-shaped waveguide was introduced as well. Two additional rods were added at the branch of the Y-shaped structure. The coupling lengths for coupled waveguides at different frequencies were calculated by the plane wave expansion method and the principle of directional coupling, and the transmission characteristics of the power splitter were analyzed and investigated by using the finite-difference time-domain method. The results show that the power splitter can split the input field into output port1 waveguide and output port2 waveguide with equal power at frequency of 1.0 THz. However, the input beam can even be split into output port3 waveguide and output port4 waveguide with an arbitrary output energy ratio at frequency of 0.893 THz by asymmetrically changed the refractive index of the two additional rods.