Chen Jiun-Yeu, Chen Lien-Wen
Department of Mechanical Engineering, National Cheng Kung University, 1, Ta-Hsueh Road, Tainan 701, Taiwan.
Phys Rev E Stat Nonlin Soft Matter Phys. 2005 Jun;71(6 Pt 1):061708. doi: 10.1103/PhysRevE.71.061708. Epub 2005 Jun 22.
An optical propagation simulation is carried out for the study of photonic defect modes in a stacked structure of cholesteric liquid crystal films with spatially varying pitch. The defects are introduced by a pitch jump and a phase jump in the cholesteric helix. The effect of a finite sample thickness on transmission of the defect mode and on the required polarization of incident light to create the defect mode is discussed. For normal and near-normal incidence of circularly polarized light with the same handedness as structure, the defect caused by a pitch jump results in discrete peaks within a forbidden band in the transmission. The particular spectrum is similar to the feature of a Fabry-Pérot interferometer. By introducing an additional phase jump, linear blueshifts of the defect modes in transmission spectra are correlated with an increase in the twist angle.
为了研究具有空间变化螺距的胆甾相液晶薄膜堆叠结构中的光子缺陷模式，进行了光传播模拟。通过胆甾相螺旋中的螺距跃变和相位跃变引入缺陷。讨论了有限样品厚度对缺陷模式传输以及产生缺陷模式所需入射光偏振的影响。对于与结构具有相同手性的圆偏振光的正入射和近正入射，由螺距跃变引起的缺陷在透射的禁带内产生离散峰。该特定光谱类似于法布里 - 珀罗干涉仪的特征。通过引入额外的相位跃变，透射光谱中缺陷模式的线性蓝移与扭曲角的增加相关。
