复合周期的介质-液晶光子晶体研究

Compound photonic crystals with cholesteric liquid crystals sandwiched isotropic defect layers

本文研究了掺入各向同性周期性介质层缺陷的一维复合周期胆甾型液晶光子晶体的禁带特性.发现同一般的胆甾型液晶不同,复合介质-液晶周期结构对左旋偏振入射光和右旋入射光都会出现共同禁带.当各向同性介质层占一个周期的厚度比例越小,左旋偏振光的禁带效应逐渐消失,而右旋偏振光的禁带则逐渐合并变大;且各向同性介质的折射率越大,则两种偏振光的禁带效应越明显,更容易出现共同禁带;通过调整厚度比,可以在可见光范围内出现对应红、绿、蓝色波长的禁带,从而可以用于液晶显示的反射式彩色滤光片.

Forbidden gaps of one-dimensional compound photonic crystals consisting of cholesteric liquid crystals sandwiched by periodic isotropic layers are investigated. The common forbidden gaps appear for both incident left and right polarization light which is different from the cholesteric liquid crystals. The forbidden gaps for incident left polarization light will disappear and the forbidden gaps for incident right polarization light will merge and become wider with the increasing of thickness ratio of cholesteric liquid crystals to periodic isotropic layers. The effect of forbidden gaps for incident left and right polarization light becomes obvious with the increasing of refractive index of periodic isotropic layers. The corresponding forbidden gaps for two colors of red,green and blue will appear by tuning thickness ratio of cholesteric liquid crystals to periodic isotropic layers and the refractive index of periodic isotropic layers,which can be used to fabricate reflective color filters for liquid display.