Neubecker R, Benkler E, Martin R, Oppo G-L
Institute of Applied Physics, Darmstadt University of Technology, Hochschulstrasse 6, 64289 Darmstadt, Germany.
Phys Rev Lett. 2003 Sep 12;91(11):113903. doi: 10.1103/PhysRevLett.91.113903. Epub 2003 Sep 10.
Defects play an important role in a number of fields dealing with ordered structures. We demonstrate theoretically and experimentally the possibility of an active manipulation of defects in terms of an externally induced motion. We focus on the spontaneous formation of two-dimensional spatial structures in a nonlinear-optical system, a liquid crystal light valve under single optical feedback. For a particular parameter setting, a spontaneously formed hexagonal intensity pattern contains several dislocation-type defects. A scheme based on Fourier filtering allows us to restore spatial order in a selectable part of the pattern. Starting without control, the controlled area is progressively expanded, such that defects are swept out of the pattern.
缺陷在许多涉及有序结构的领域中起着重要作用。我们通过理论和实验证明了根据外部诱导运动对缺陷进行主动操纵的可能性。我们关注非线性光学系统（单光反馈下的液晶光阀）中二维空间结构的自发形成。对于特定的参数设置，自发形成的六边形强度图案包含几个位错型缺陷。基于傅里叶滤波的方案使我们能够在图案的可选择部分恢复空间秩序。从无控制开始，受控区域逐渐扩大，从而将缺陷从图案中清除。
