Photoalignment of liquid crystals by liquid crystals
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.
Reznikov
Y
Institute of Physics of National Academy of Science, Prospect Nauki 46, Kyiv 252022, Ukraine.
Ostroverkhova
O
Singer
KD
Kim
JH
Kumar
S
Lavrentovich
O
Wang
B
West
JL