Mg. Clerc et al., First-order Freedericksz transition in the presence of light-driven feedback in nematic liquid crystals - art. no. 060701, PHYS REV E, 6306(6), 2001, pp. 0701
We show that feedback, which introduces a dependence of the electric field
on the liquid-crystal director, renders the Freedericksz transition first o
rder. Experimentally, the feedback is introduced as a light loop in a liqui
d-crystal light valve. Theoretically, we include the feedback term into the
Frank free energy and we derive an amplitude equation that is valid close
to the transition. The theoretical description is in qualitative agreement
with the experimental observations. Depending on the values of the feedback
parameters, both theory and experiment exhibit bistability, propagation of
fronts, and a Maxwell point.