Department of Physics, Yerevan State University, 1 Alex Manoogian Street, 0025 Yerevan, Armenia.
Phys Rev E. 2019 Jan;99(1-1):012702. doi: 10.1103/PhysRevE.99.012702.
In this paper, we consider the optical properties of cholesteric liquid crystals (CLCs) with a dye. We investigate the reflection, transmission, and absorption spectra peculiarities. We show that in the presence of dye molecules, in certain conditions, the photonic band gap (PBG) splits into two, three, etc., PBGs. A simple geometric method for determination of the Bragg frequencies and the widths of forbidden bands is proposed. It is shown that we can change the Bragg frequencies and the widths of forbidden bands by changing the parameters of dye molecules. We investigate the light localization peculiarities in the CLC layer in the presence of dye molecules. The peculiarities of the spectra of the photonic density of states and the spectra of light energy density in the CLC layer are also investigated. We show that in the presence of two types of resonances the observation of Fano resonance is possible. The peculiarities of Fano resonance in the CLC with dyes are investigated. We show that this system can be used for achieving a narrow bandwidth spectral response in transmission or reflection.
在本文中，我们研究了带有染料的胆甾相液晶（CLC）的光学性质。我们研究了反射、透射和吸收光谱的特点。我们表明，在存在染料分子的情况下，在某些条件下，光子带隙（PBG）会分裂成两个、三个等多个 PBG。提出了一种用于确定布拉格频率和禁带宽度的简单几何方法。结果表明，通过改变染料分子的参数，可以改变布拉格频率和禁带宽度。我们研究了存在染料分子时 CLC 层中的光局域化特性。还研究了 CLC 层中光子态密度谱和光能量密度谱的特点。结果表明，在存在两种类型的共振的情况下，有可能观察到 Fano 共振。研究了染料 CLC 中的 Fano 共振的特点。结果表明，该系统可用于在透射或反射中实现窄带宽光谱响应。
