Francés Jorge, Bleda Sergio, Puerto Daniel, Gallego Sergi, Márquez Andrés, Neipp Cristian, Pascual Inmaculada, Beléndez Augusto
Instituto Universitario de Física Aplicada a las Ciencias y las Tecnologías, Universidad de Alicante, 99, 03080 Alicante, Spain.
Departamento de Física, Ing. de Sistemas y Teoría de la Señal, Universidad de Alicante, 99, 03080 Alicante, Spain.
Materials (Basel). 2020 Aug 23;13(17):3725. doi: 10.3390/ma13173725.
This work presents recent results derived from the rigorous modelling of holographic polymer-dispersed liquid crystal (H-PDLC) gratings. More precisely, the diffractive properties of transmission gratings are the focus of this research. This work extends previous analysis performed by the authors but includes new features and approaches. More precisely, full 3D numerical modelling was carried out in all analyses. Each H-PDLC sample was generated randomly by a set of ellipsoid geometry-based LC droplets. The liquid crystal (LC) director inside each droplet was computed by the minimisation of the Frank elastic free energy as a function of the applied electric field. The analysis carried out considered the effects of Frank elastic constants K11, K22 and K33; the anchoring strength W0; and even the saddle-splay constant K24. The external electric field induced an orientation of the LC director, modifying the optical anisotropy of the optical media. This effect was analysed using the 3D split-field finite-difference time-domain (SF-FDTD) method. In order to reduce the computational costs due to a full 3D tensorial analysis, a highly optimised method for high-performance computing solutions (HPC) was developed. The influences of the anchoring and voltage on the diffraction efficiencies were investigated, showing the potential of this approach.
这项工作展示了近期从全息聚合物分散液晶(H-PDLC)光栅的严格建模中得出的结果。更确切地说,透射光栅的衍射特性是本研究的重点。这项工作扩展了作者之前进行的分析,但包含了新的特征和方法。更确切地说,在所有分析中都进行了完整的三维数值建模。每个H-PDLC样品由一组基于椭球体几何形状的液晶微滴随机生成。通过将弗兰克弹性自由能作为外加电场的函数进行最小化,计算每个微滴内的液晶指向矢。所进行的分析考虑了弗兰克弹性常数K11、K22和K33的影响;锚定强度W0;甚至鞍形展曲常数K24。外部电场引起液晶指向矢的取向,改变了光学介质的光学各向异性。使用三维分裂场时域有限差分(SF-FDTD)方法分析了这种效应。为了降低由于完整的三维张量分析而产生的计算成本,开发了一种用于高性能计算解决方案(HPC)的高度优化方法。研究了锚定和电压对衍射效率的影响,展示了这种方法的潜力。