title: Photoalignment of liquid crystals by liquid crystals
abstract: We observed light-induced alignment of the nematic liquid crystal, 4, 4(')-n-pentylcyanobiphenyl (5CB), on a fused quartz. Irradiation of the adsorbed layer with polarized ultraviolet light produced homogeneous alignment in a 5CB-filled liquid crystal cell with the easy orientation axis perpendicular to the polarization direction. The measured anchoring energy increases with illumination up to 10(-4) erg/cm (2). Phase retardation and pretilt measurements confirmed near homogeneous alignment of the LC in a cell, while the polarization dependence of second harmonic generation suggested a near normal alignment of the adsorbed layer. We believe that light-induced rearrangement or phototransformation of the adsorbed layer causes the observed phenomenon.
authors.affiliation: Institute of Physics of National Academy of Science, Prospect Nauki 46, Kyiv 252022, Ukraine.
authors.initials: Y
authors.lastname: Reznikov
authors.initials: O
authors.lastname: Ostroverkhova
authors.initials: KD
authors.lastname: Singer
authors.initials: JH
authors.lastname: Kim
authors.initials: S
authors.lastname: Kumar
authors.initials: O
authors.lastname: Lavrentovich
authors.initials: B
authors.lastname: Wang
authors.initials: JL
authors.lastname: West