<title>Alignment of dye-doped liquid crystal in nematic phase after irradiation of liquid crystal in isotropic phase</title>

Abstract

The effect of a hidden photoalignment of nematic liquid crystal (LC) after the irradiation of the cell with linearly polarized light in the isotropic phase was recently observed (Phys.Rev.E, 021701, <b>63</b>, (2001). It was found that the effect was caused by light-induced desorption and adsorption of dopant dye molecules on the aligning surface. The desorption of the dye molecules resulted in the anisotropy axis perpendicular to the light polarization whereas the light-induced adsorption causes the anisotropy parallel to the light polarization vector. Competition between these processes determined the resulting direction of the easy axis in a nematic phase. In the present paper we distinguished these two mechanisms by using different geometries of the irradiation of the cell.