Physical Review Letters
2Nd Harmonic Generation, Ultraviolet Light, Alignment, Surface, Orientation, Monolayers, Films
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 thr 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, Yuriy; Ostroverkhova, Oksana; Singer, Kenneth D.; Kim, Jae-Hoon; Kumar, Satyendra; Lavrentovich, Oleg; Wang, Bin; and West, John L. (2000). Photoalignment of Liquid Crystals By Liquid Crystals. Physical Review Letters 84(9), 1930-1933. doi: 10.1103/PhysRevLett.84.1930 Retrieved from http://digitalcommons.kent.edu/phypubs/55