Tuning the effective width of the optical stop band in colloidal photonic crystals
Tuning the effective width of the optical stop band in colloidal photonic crystals
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DOI：
10.1021/la0621160
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发表时间：
2007-03-27
期刊：
影响因子：
3.9
通讯作者：
Kitamura, Kenji
中科院分区：
文献类型：
--
作者：
Kanai, Toshimitsu;Sawada, Tsutomu;Kitamura, Kenji
用中心频率和带宽表征了胶体晶体中的光学阻带。虽然前者通过改变晶格常数可以高度调谐，但后者基本上是由粒子和材料固有的背景介质之间的折射率对比度决定的。在这项研究中，我们发现凝胶胶体晶体的有效带宽也可以通过控制制备条件来调节。在不同的光照条件下，采用光聚合法制备了单区凝胶胶体晶体。观察到，只要简单地调整辐照时间，就可以扩展透射谱或反射谱中的阻带宽度。
The optical stop band in colloidal crystals is characterized by the central frequency and bandwidth. Although the former is known to be highly tunable by changing the lattice constant, the latter is basically determined by the refractive index contrast between the particles and the background medium that is intrinsic to the materials. In this study, we show that the effective bandwidth in gelled colloidal crystals can also be tuned by controlling the fabrication conditions. Single-domain gelled colloidal crystals were prepared by photopolymerization under various photoirradiation conditions. It was observed that the width of the stop band in the transmission or reflectance spectrum could be expanded by simply adjusting the irradiation time.