Optics Letters

Anomalous wavelength dependence of the dye-induced optical reorientation in nematic liquid crystals


We report on Z-scan measurements of the spectral dependence of dye-induced enhancement of optical torque in nematic liquid crystals. It is found that the enhancement factor changes sign from positive to negative as photon energy increases from 2.4 to 2.7 eV. Modification of our earlier model is proposed to describe the observed spectral dependence.