可调谐液晶光子晶体是通过加电场、光场或改变液晶温度来改变液晶指向矢的方向，进而改变液晶折射率达到控制光子带隙的目的。运用平面波展开法（PWM）对圆柱、方柱及正六边柱构造的二维可调谐液晶三角格子光子晶体的禁带进行仿真模拟，讨论了基底材料分别为Ge和Si情况下，柱子形状、旋转角度和填充比的变化对二维苯乙炔型液晶光子带隙的影响。发现均无完全光子禁带出现，而通过改变液晶折射率可得到大调谐范围的TE偏振光。该结构参数可为制造大调谐范围的场敏偏光片提供理论上的指导、同时也为波导光开关、可调谐滤波器和光衰减器的研制提供理论上的根据。

Tunable photonic crystal (PC) can control photonic band gap through changing the refractive index of liquid crystal (LC) by adding an electric filed, optical field or changing its temperature, which can change the orientation of LC′s direction vector. Plane-wave expansion method (PWM) is used to simulate the band gap of 2D tunable triangular lattice PC with structure of cylinder, square column and regular hexahedron column. The influence of changing rods shape, rotation angle and filling ratio on 2D phenylacetylene LC photonic band gap(PBG) are discussed when the substrate materials are Ge and Si respectively. It is find that there isn′t any absolute PBG in any condition, but big tuning range of TE polarized wave can be achieved by changing the index of liquid crystal. This structural parameter can provide theoretical instruction for field sensitive polarizer with great tuning range, and foundation of triturating waveguide optical switch, tunable filter and optical attenuator.