Optically induced dynamics in nematic liquid crystals: The role of finite beam size.
We report on the influence of a finite beam size on the molecular reorientation dynamics when a nematic liquid crystal film is excited by a laser beam. We present experimental evidence of a new class of nonlinear dynamics when the excitation is a Gaussian shaped, circularly polarized laser beam at normal incidence. Various nonlinear regimes, periodic, quasiperiodic, intermittent, and possibly chaotic, are observed. A physical interpretation based on walk-off effects is proposed and its implications on current research in the field are discussed.
Brasselet
E
E
Laboratoire de Photonique Quantique et Moléculaire, Ecole Normale Supérieure de Cachan, 94235 Cachan Cedex, France. ebrassel@lpqm.ens-cachan.fr
Doyon
B
B
Galstian
T V
TV
Dubé
L J
LJ