Laser-directed hierarchical assembly of liquid crystal defects and control of optical phase singularities.
Topological defect lines are ubiquitous and important in a wide variety of fascinating phenomena and theories in many fields ranging from materials science to early-universe cosmology, and to engineering of laser beams. However, they are typically hard to control in a reliable manner. Here we describe facile erasable "optical drawing" of self-assembled defect clusters in liquid crystals. These quadrupolar defect clusters, stabilized by the medium's chirality and the tendency to form twisted configurations, are shaped into arbitrary two-dimensional patterns, including reconfigurable phase gratings capable of generating and controlling optical phase singularities in laser beams. Our findings bridge the studies of defects in condensed matter physics and optics and may enable applications in data storage, singular optics, displays, electro-optic devices, diffraction gratings, as well as in both optically- and electrically-addressed pixel-free spatial light modulators.
Department of Physics and Liquid Crystal Materials Research Center, University of Colorado, Boulder, Colorado 80309, USA.
Paul J
PJ
Ackerman
Zhiyuan
Z
Qi
Yiheng
Y
Lin
Christopher W
CW
Twombly
Mauricio J
MJ
Laviada
Yves
Y
Lansac
Ivan I
II
Smalyukh
D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D007834:Lasers; D050866:Liquid Crystals / Q000737:chemistry*; D018613:Microscopy, Confocal / Q000295:instrumentation / Q000379:methods; D008859:Microscopy, Polarization / Q000295:instrumentation / Q000379:methods; D055096:Optical Devices; D055620:Optical Phenomena; D012031:Refractometry; D015203:Reproducibility of Results