On the mechanism of light-induced orientation of molecules in absorbing nematic liquid crystals

A new mechanism is proposed for the collective light-induced rotation of orientationally ordered molecules of absorbing nematic liquid crystals. The mechanism derives from the noncentral character of the light-induced change in the interaction potential of the excited and unexcited molecules and also from the anisotropy of their correlation function. Rotation is produced by the difference of the torques exerted by the intermolecular forces orienting the ensembles of excited and unexcited molecules. Pis’ma Zh. éksp. Teor. Fiz. 68, No. 5, 410–414 (10 September 1998)