应用平行向列相液晶作为光子晶体缺陷层设计了一种可调谐滤波器。用4×4矩阵方法，详细讨论了入射角对本征透射模式的影响。结果表明，入射角小于10°时，透射模式波长主要由外加电压决定，此范围内，可进行电压调谐，通过其偏振敏感性选择透射模式；入射角大于10°时，透射模式波长向短波方向移动，且两透射模式变化不一致，因此外加电压大于8V时，可以进行角度调谐，通过改变入射角选择透射模式，使调谐范围增大，同时也增大了实际应用的灵活性。

A tunable photonic crystal filter is proposed with parallel nematic liquid crystal as defect layer. The transmission modes while varying incident angle are discussed in detail by 4×4 matrix method. The results show that transmission modes are mainly decided by the voltage when the incident angle is smaller than 10°. In this region, the transmission modes can be tuned by voltage and different modes can be selected based on polarization sensitive performance. When the incident angle is greater than 10°, the peaks of two modes shift toward the shorter wavelength side and the change of two modes is different. So the transmission modes can be tuned and selected by varying the incident angle in the voltage region of more than 8 V. Both the tunable range and the flexibility of application are enlarged.