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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 18, Iss. 2 — Jan. 18, 2010
  • pp: 500–506

Janus Nematic Colloids driven by light

M. Conradi, M. Zorko, and I. Muševič  »View Author Affiliations

Optics Express, Vol. 18, Issue 2, pp. 500-506 (2010)

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We present an experimental analysis of different equilibrium orientations and light driven transformations of Janus particles in the nematic liquid crystal 5CB. Depending on the preparation technique of homeotropic (DMOAP) and planar (Au) hemispheres we have observed two types of director field configurations: dipolar-like in the case of Au/DMOAP capped colloids and boojum-like in the case of DMOAP/Au capped colloids. Using the manipulation of Au/DMOAP capped colloids with laser tweezers we report on light driven irreversible orientational transformations into Saturn-ring and a novel, boojum-ring configuration. On the contrary, boojum-like DMOAP/Au capped colloids can act as rotators when exposed to the laser filed. Observed rotation is continuous around an axis perpendicular to the laser beam axis, with the frequency increasing linearly with the laser power.

© 2010 OSA

OCIS Codes
(160.3710) Materials : Liquid crystals
(350.3950) Other areas of optics : Micro-optics
(350.4855) Other areas of optics : Optical tweezers or optical manipulation

ToC Category:

Original Manuscript: September 28, 2009
Revised Manuscript: November 19, 2009
Manuscript Accepted: December 13, 2009
Published: January 4, 2010

M. Conradi, M. Zorko, and I. Muševič, "Janus Nematic Colloids driven by light," Opt. Express 18, 500-506 (2010)

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