Effect of light on the polarization of a banana-shaped achiral compound doped with a photoactive azobenzene material

We report photoinduced effects on a liquid crystal comprising of bent-core molecules, doped with a photoactive azobenzene compound and exhibiting the recently discovered "banana" B-2 mesophase. The photoisomerization of the a zobenzene molecules, brought about by the UV radiation, hardly changes the B-2-isotropic transition temperatures, but has a significant influence on t he spontaneous polarization (Ps) as well as the switching time in the B-2 p hase. The efficiency of this opto-polarization effect has been observed to be strongly dependent on the temperature at which the irradiation is carrie d out. A possible mechanism responsible for the observed phenomenon has bee n suggested. (C) 2001 American Institute of Physics.