One-dimensional transport-induced instabilities in an optical system with nonlocal feedback.

We present theoretical and experimental evidence of pattern forming instabilities induced by the nonlocal interaction of the light signal with itself, in an optical system formed by a liquid-crystal light valve with feedback. For a defocusing medium, the model predicts a reduced instability threshold for pattern formation as a result of nonlocality. The conditions for the onset of drifting mode instability are analytically derived. The experimental results quantitatively confirm the predictions of the model.