Brasselet Etienne, Murazawa Naoki, Juodkazis Saulius, Misawa Hiroaki
Laboratoire CPMOH Université Bordeaux 1, Centre National de la Recherche Scientifique, 351 Cours de la Libération, Talence Cedex, France.
Phys Rev E Stat Nonlin Soft Matter Phys. 2008 Apr;77(4 Pt 1):041704. doi: 10.1103/PhysRevE.77.041704. Epub 2008 Apr 15.
Laser manipulation of trapped radial 4'-n-pentyl-4-cyanobiphenyl (5CB) nematic liquid-crystal droplets induced by molecular reordering is presented. We show experimentally that optical tweezers having linear, elliptical, or circular polarization can break the radial symmetry of the initial molecular organization inside a radial nematic droplet. Static distorted or twisted deformation modes and steady or unsteady nonlinear rotational dynamics are observed. Statics results are analyzed in terms of light-induced radial or left-right symmetry breaking effects associated with optical reorientation. The dynamical observations are compared with simulations from a slab analog model, for which orientational processes driven by optical nonlinearities can be accurately described. This study confirms that light-induced bulk reordering is an essential ingredient towards the understanding of the behavior of radial nematic liquid-crystal droplets in laser tweezers, as suggested by previous studies.
本文介绍了通过分子重排对捕获的径向4'-正戊基-4-氰基联苯（5CB）向列型液晶微滴进行激光操纵的方法。我们通过实验表明，具有线性、椭圆形或圆形偏振的光镊可以打破径向向列型微滴内部初始分子排列的径向对称性。观察到了静态扭曲或扭曲变形模式以及稳定或不稳定的非线性旋转动力学。根据与光学重取向相关的光致径向或左右对称性破缺效应，对静态结果进行了分析。将动力学观测结果与平板模拟模型的模拟结果进行了比较，该模型可以准确描述由光学非线性驱动的取向过程。如先前研究所暗示的那样，本研究证实光致整体重排是理解径向向列型液晶微滴在激光镊子中行为的重要因素。
