Issue
EPL
Volume 88, Number 5, December 2009
Article Number 56003
Number of page(s) 6
Section Condensed Matter: Structural, Mechanical and Thermal Properties
DOI http://dx.doi.org/10.1209/0295-5075/88/56003
Published online 11 December 2009
EPL, 88 (2009) 56003
DOI: 10.1209/0295-5075/88/56003

Investigation of enhancement of photoinduced reorientation of liquid-crystal molecules in the presence of azo-dye and gold nanoparticles

P. Karpinski and A. Miniewicz

Institute of Physical and Theoretical Chemistry, Wroclaw University of Technology - Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland, EU

pawel.karpinski@pwr.wroc.pl

received 25 September 2009; accepted in final form 13 November 2009; published December 2009
published online 11 December 2009

Abstract
The optical-Kerr-effect configuration is used to study the enhancement of photo-induced molecular reorientation in a twisted nematic liquid crystal due to the presence of metal nanoparticles. The system consisting of a liquid crystal with photoisomerizable dye Disperse Orange 3 shows an enhancement of the Kerr-like response at 532 nm excitation light when doped with 15 nm in size gold nanoparticles. A simple theoretical model predicting the behavior and magnitude of the expected response has been formulated. The contribution of localized surface plasmon of gold nanoparticles to light-induced torque is discussed.

PACS
61.30.-v - Liquid crystals.
42.65.-k - Nonlinear optics.
77.84.Nh - Liquids, emulsions, and suspensions; liquid crystals.

© EPLA 2009