Eur. Phys. J. D 28, 435-445 (2004)
https://doi.org/10.1140/epjd/e2003-00316-1

First-order Fréedericksz transition and front propagation in a liquid crystal light valve with feedback

¹ Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Casilla 487-3, Santiago, Chile
² Department of Electrical and Electronic Engineering, Faculty of Engineering, Okayama University, Japan
³ Physics Department, Yerevan St. University 1, A. Manoogian st. 375049 Yerevan, Armenia
⁴ Institut Non Linéaire de Nice, UMR 6618 CNRS-UNSA, 1361 route des Lucioles, 065600 Valbonne, France
⁵ DAMTP-CMS, Wilberforce Road, Cambridge CB3 0WA, UK

Corresponding author: ^a residori@inln.cnrs.fr

Received: 1 August 2003
Revised: 21 October 2003
Published online: 6 January 2004

Abstract

Fréedericksz transition can become subcritical in the presence of a feedback mechanism that leads to the dependence of the local electric field onto the liquid crystal re-orientation angle. We have characterized experimentally the first-order Fréedericksz transition in a Liquid Crystal Light Valve with optical feedback. The bistability region is determined, together with the Fréedericksz transition point and the Maxwell point. We show the propagation of fronts connecting the different metastable states and we estimate the front velocity. Theoretically, we derive an amplitude equation, valid close to the Fréedericksz transition point, which accounts for the subcritical character of the bifurcation.