填充液晶的光子晶体的光控可调光子带隙

Photoalignment Tunable Band Gap in Photonic Crystal Infiltrated with Liquid Crystal

可调光子晶体由于其潜在的应用价值成为现今光子晶体研究中的一个热点。文章首次提出了通过光诱导液晶取向技术来调制光子晶体光子禁带的方法,进而采用平面波展开法分析了填充液晶的二维三角形光子晶体禁带结构的可调节性。数值模拟结果表明:通过偏振光控制空气孔中所填充的相列液晶的方向可以对光子晶体的禁带结构进行调节。与电场调制方法相比,该光控液晶取向技术具有响应速度快、结构简单的优点。这种可调光子晶体可用于制作场敏偏光片、全光光开关和可调光衰减器。

Tunable band gap is a new and important field in photonic crystals research because of many potential applications. This paper reported the method of modulating the photonic band gap firstly by light induced alignment of liquid crystals. The band properties of two-dimensional and triangular lattices photonic crystal modulated by a nematic liquid were investigated numerically by using the plane wave expansion method. It shows that the band gaps can be continuously tuned by manipulating the LC photoinduced alignment, which has the advantages of fast response and low cost compared to the tunable method through an external electric field. The results imply that this method have potential application in polarizer, all-optical switches and VOA.