LIGHT-INDUCED FREEDERICKSZ TRANSITION IN A NEMATIC LIQUID-CRYSTAL WITH CHIRAL DOPANT

The influence of phototransformed molecules with chiral properties cha nging on the absorption of light held on the light-induced Freedericks z transition threshold in a homeotropically oriented nematic cell is c onsidered. It is shown that the appearance of the light-induced chiral molecules can decrease or increase the Freedericksz threshold value d epending on the chirality sign of the phototransformed molecules and o f the initial chiral dopant. Expressions for the threshold are obtaine d for circular and linear polarization of the incident light. The depe ndence of the threshold on the periodicity of the spatially modulated light intensity is estimated for large periods of modulation. The depe ndence of dopant threshold chirality on the director anchoring energy has been found.