title: Nonphotochemical laser-induced nucleation of nematic phase and alignment of nematic director from a supercooled thermotropic liquid crystal.
abstract: A nonphotochemical laser-induced phase transition was studied in a supercooled 4;{'}-n -pentyl-4-cyanobiphenyl (5CB, also referred to as PCB and K15) liquid crystal, using linearly polarized 45 ps light pulses at a wavelength of 532 nm. The laser induced nucleation from the metastable supercooled isotropic phase to the nematic phase during slow cooling (0.001 degrees C/min) and high light intensity (3.9 MW/cm{2}) . The resulting nematic director tended to be aligned along the direction of the plane of polarization of the light. At the intensities used, there is no observable laser-induced realignment of the director once the sample is in the nematic phase, nor any permanent laser-induced ordering when the sample is illuminated only in the stable isotropic phase during slow cooling. These experimental results are consistent with a mechanism based on optical Kerr alignment.
authors.affiliation: Department of Chemical and Biological Sciences, Polytechnic Institute of New York University, Brooklyn, New York 11201, USA.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Sun
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Garetz
authors.forename: Michele F
authors.initials: MF
authors.lastname: Moreira
authors.forename: Peter
authors.initials: P
authors.lastname: Palffy-Muhoray