比较研究了液晶分子平行和扭曲排列对TiO2和SiO2介质膜交替的一维光子晶体透射谱的影响。向列相液晶平行取向时,光子禁带中出现四个透过峰,中心波长约1840、1814、1466、1423nm,加热器件,峰位蓝移,相邻的两个透过峰合二为一。向列相液晶扭曲排列时,光子禁带中出现两个独立透射峰.分别位于1865、1489nm,加热样品峰位蓝移。液晶分子平行排列,液晶层折射率各向异性较明显,光子禁带具有两种偏振模式透过峰。液晶分子扭曲排列,液晶层折射率各向异性不明显,光子禁带只有独立透过峰。加热样品,液晶分子排列变化,引起液晶层有效折射率值改变,透过峰位移动。
The effect of the arrange of LC molecular on the transmission spectrum in the one-dimensional photonic crystals of a turn of the TiO2 and SiO2 dielectric film was studied, parallel and twist, respectively. It appeared four transparent peaks in photonic band gap when parallel orientation of the nematic LC, the central wavelengths were approximately at 1 840, 1 814, 1 466 and 1 423 nm. Then heating the device, the peak position would blue shift, and the adjacent transparent peak would overlapping. It appeared two independent transmission peaks in photonic band gap, whose position were at 1865, 1489 nm, respectively, when twist arrange of the nematic LC. Heating sample, the peak position appeared blue shift. The refractive index anisotropy was more pronounced in the nematic LC layer of the parallel orientation and had two polarization transparent peaks. However, with the twist arrange of the nematic LC, refractive index anisotropy was not obvious, photonic band gap only had one independent transparent peaks. LC molecular orientation could be changed when heating sample, and causing the effectiverefractive index of the LC layer change, so that to move the position of transparent peaks.