为了实现结构紧凑、高透射率的解波分复用功能，在二维三角晶格光子晶体平板上设计了一个ψ形的三通道解波分复用器.通过在该光子晶体结构中引入合适的线缺陷和点缺陷，使得在光子禁带中出现了局域缺陷态.利用该缺陷态模式，可以控制波的传播和耦合，从而实现解波分复用的功能.通过用平面波扩展法和时域有限差分法对此解波分复用器进行了能带和传输特性分析，找到了具有合适缺陷态频率的光子晶体结构参量，实现了透过率高达80%的解波分复用功能.

In order to realize the function of wavelength division multiplexing(WDM) device with compact structure and high transmittance, a ψ-shape three-channel wavelength division multiplexing device is designed on the triangle lattice photonic crystals which are composed of Si medium columns. Defect modes are produced in the photonic band gap by the introduction of line defects a point defects, the propagation and coupling of light in the photonic crystals are controlled by taking advantage of the defect modes, and the function of solution WDM are thus realized. The band gap and transmission characteristic of the solution WDM were analysed using plane-wave expansion and finite deference time domain method. The parameters of photonic crystal structure with proper defect mode frequency were found and the function of solution WDM with transmittance of 80% was realized.