J. Phys. II France
Volume 5, Numéro 1, January 1995
Page(s) 133 - 142
DOI: 10.1051/jp2:1995118
J. Phys. II France 5 (1995) 133-142

Photoinduced Optical Anisotropy in Langmuir Blodgett Films as a New Method of Creating Bistable Anchoring Surfaces for Liquid Crystal Orientation

S. P. Palto, S. G. Yudin, C. Germain and G. Durand

Laboratoire de Physique des Solides (LA2), Université de Paris Sud, 91405 Orsay, France

(Received 29 December 1993, revised 21 September 1994, accepted 12 October 1994)

We report a new method to prepare surfaces that creates two degenerate states for liquid crystal orientation. The method uses Langmuir-Blodgett (LB) films exhibiting the effect of photoinduced optical anisotropy. We illuminate LB films twice with polarized light of perpendicular orientations to produce a special shape for the molecular distribution function in a LB film. Nematic liquid crystal molecules (NLC) aligned by these films can show two stable orientations, i.e. surface induced bistability. The results observed are interpreted in terms of a micro domain distribution in LB film. The origin of the bistability is "extrinsic".

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