Physical Review E
aqueous urea solutions, polarization dependence, reorientation
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 °C∕min) and high light intensity (3.9 MW∕cm2). 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.
Sun, Xiaoying; Garetz, Bruce A.; Moreira, Michele F.; and Palffy-Muhoray, Peter (2009). Nonphotochemical Laser-Induced Nucleation of Nematic Phase and Alignment of Nematic Director from a Supercooled Thermotropic Liquid Crystal. Physical Review E 79(2). doi: 10.1103/PhysRevE.79.021701 Retrieved from http://digitalcommons.kent.edu/cpippubs/107