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

The optical-Kerr-effect configuration is used to study the enhancement of photoinduced 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. Copyright (C) EPLA, 2009