Photoinduction of nematic order in isotropic phase

Abstract
The induction of orientational order close to a surface has been observed for an isotropic diacetylene compound under pulsed laser illumination into its absorption band. The value of the induced birefringence is proportional to the square of the intensity of the absorbed light. The direction of the photoinduced optical axis is defined both by the substrate surface and the light polarization vector. The observed phenomenon is explained by photoinduction of fluctuations of the nematic order in the vicinity of the surface and reorientation of these fluctuations under the polarized light illumination.