Tunable photonic band gap crystals based on a liquid crystal-infiltrated inverse opal structure
Tunable photonic band gap crystals based on a liquid crystal-infiltrated inverse opal structure
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DOI：
10.1021/ja0495056
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发表时间：
2004-07-07
影响因子：
15
通讯作者：
Sato, O
中科院分区：
文献类型：
--
作者：
Kubo, S;Gu, ZZ;Sato, O
制备了由SiO2反蛋白石薄膜和反蛋白石液晶组成的复合材料。它们的光学性质与没有液晶的反蛋白石薄膜有很大的不同。可以通过改变液晶的折射率来控制其光学性质，液晶的折射率随取向、相位和温度而变化。特别是，液晶的热致或光致等温相变会极大地改变光学性质。这意味着基于反蛋白石结构可以控制光子晶体的能带结构，并实现可调谐光子晶体。这种变化的机制进行了研究的有效折射率的评价。结果发现，光学性质的变化来自反蛋白石膜中空隙中的LC分子的取向。此外，一旦理解了该机制，还可以通过改变LC的排列来控制反射峰的位置。这种材料有可能在光学器件和基础研究系统中得到实际应用。
Composite materials comprised of nematic liquid crystals (LCs) and SiO2 inverse opal films were fabricated. Their optical properties were quite different from those of inverse opal films without the LCs. The optical properties could be controlled by changing the refractive indices of the LCs, which vary with orientation, phase, and temperature. In particular, the optical properties were drastically changed by thermal or photoinduced isothermal phase transitions of the LCs. This means that the photonic band structure could be controlled, and tunable photonic crystals have been achieved, based on the inverse opal structure. The mechanism of this change was investigated by the evaluation of the effective refractive indices. As a result, it was found that the change in optical properties was derived from the orientation of the LC molecules in the voids in the inverse opal film. Furthermore, once the mechanism was understood, it was also possible to control the position of the reflection peak by changing the alignment of the LCs. Such materials have the possibility for practical use in optical devices and fundamental research systems.