Alignment characteristic of nematic liquid crystals on orientational patterns realized by interfering laser light

Abstract

We have observed the alignment property and switching behaviour of nematic liquid crystals (NLCs) on orientation patterns that were realized on a photo-active alignment layer by using interferring beams of two coherent laser lights. Linearly polarized light orients the liquid crystals in a direction perpendicular to the polarization and the interferring laser light induced a one-dimensional periodic texture following the interference pattern. Using double irradiation, in which the direction of the second irradiation was rotated by 90° to the first irradiation, we constructed a quasi-four-fold symmetric orientation pattern. The NLCs exhibited bistability in two average directions of polarization of the laser light, and they stably switched between the two directions by the in-plane electric field. Furthermore, the NLCs indicated the capability of continuous and memorized switching with a changing electric field on the orientation pattern.