J. Phys. I France
Volume 7, Numéro 9, September 1997
Page(s) 1143 - 1153
DOI: 10.1051/jp1:1997113
J. Phys. I France 7 (1997) 1143-1153

The Decay of Unstable Orientational States of Nematic Liquid Crystals Interacting with a Laser Field

G. Cipparrone1, D. Duca1, C. Versace1, C. Umeton1 and N.V. Tabiryan2

1  Istituto Nazionale per la Fisica della Materia, Unitá di Cosenza and Dipartimento di Fisica, Universitá della Calabria, 87036 Rende (CS), Italy
2  Center for Research and Education in Optics and Lasers (CREOL), University of Central Florida, P.O. Box 162700, Orlando, FL 32816-2700, USA

(Received 15 July 1996, received in final form 21 May 1997, accepted 26 May 1997)

We show that the rate of relaxation is an important characteristic of the dynamics of critical systems undergoing second order phase transition, which are, in fact, still in effective motion even after the order parameter is reaching its steady state value. As a model system, we investigate the instability of the orientational state of a nematic liquid crystal acted on by a laser field and present the measurement of the initial fluctuations that start up the decay of the unstable state.

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