Ordering of a.c. electric-field-induced domains in dye-doped nematics under photoexcitation

Electrohydrodynamic instabilities arising with a.c. electric field applied to planar-oriented cells filled with anthraquinone dye-doped multicomponent nematic mixture have been studied by diffraction methods. It has been found that c.w. He-Ne laser radiation of small power (~1 mW) exerts ordering effect on the LC layer domain structure. The ordered structure can persist in the presence of the same a.c. electric field for a few tens of minutes. The size of periodic optical irregularity has been calculated.