PETROSYAN , Artyom

We show that a very large optical response is obtained in azo-dyedoped nematic liquid crystals for low input light intensities (of the order of a few tens of µW/cm2 and that this extreme sensitivity of the nematic film results from a combined action of the photoisomerization process of the azo-dye molecules and the light-induced changes of the...

Experimental evidence of bouncing localized structures in a nonlinear optical system is reported.

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e report new advancements in the experimental investigation of the giant optical nonlinearity observed in azo-dye doped nematic liquid crystals. We show that the extreme sensitivity of the azo-dye doped nematics results from a combined action of the trans-cis photoisomerization process of the azo-dye molecules and the light-induced changes of...

In this article we review the conditions for the appearance of localized states in a nonlinear optical system, with particular reference to the liquid crystal light valve (LCLV) experiment. The localized structures here described are of dissipative type; that is, they represent the localized solutions of a pattern-forming system. We discuss...

In a photorefractive liquid crystal light valve, acting as a Kerr-like nonlinear optical medium, we show the appearance of optical patterns induced by a single mirror feedback. The spatial wavelength of the patterns scales with the distance between the mirror and the valve and the contrast of the patterns decreases for decreasing this distance....

We show that in a liquid-crystal-light-valve with optical feedback the Fréedericksz transition displays a subcritical character. Experimentally, we determine the extension of the bistable region and we study the propagation of fronts connecting the different metastable states. Theoretically, we derive an amplitude equation, valid close to the...

réedericksz 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...