Optical diffractometry of anisotropic holographic structure composed of liquid crystal and polymer phases with extended Bragg modes

Diffraction spectra at several Bragg modes of holographic polymer dispersed liquid crystals (HPDLCs) were measured individually for two orthogonal polarizations at temperatures below and above nematic-to-isotropic point. Then optical structures of the HPDLCs were quantitatively analyzed based on advanced two-wave coupled wave theory by fitting calculations consistently all at once to the measured diffraction data at not only the first Bragg mode but also the higher order ones, which has never been demonstrated before. The present analysis provided the microscopic information such as the polarization and temperature dependences on harmonic sinusoidal profiles of refractive-index modulation along grating vector, and was examined in validity by comparison with phase-separated morphology observed by scanning electron microscopy. The present analysis allowed you to find the technologically-advanced information, that is, the controllability of fine configuration of LC/polymer phase distribution and the optical anisotropy in the fabrication process. (C) 2013 Elsevier B.V. All rights reserved.