Surface-localized electromagnetic fields can induce strong reorientation of liquid crystals (LC’s), thus making it possible to observe a whole new class of opto-electronic phenomena. We show the feasibility of reorientation of a LC by a spatially inhomogeneous electric field localized on a photorefractive substrate. The modulation of the space-charge density in the plane of the photorefractive substrate generates a component of the electric field, which is normal to the LC layer. The drift of ions enforced by that field can result in a surface-charge modulation pattern that can become permanent owing to adsorption of ions at the boundaries of the LC cell. The obtained results present large fundamental and practical interest for the visualization of surface-localized electric fields and the development of new principles of optical information processing and storage.
[Optical Society of America ]
(160.3710) Materials : Liquid crystals
(190.5330) Nonlinear optics : Photorefractive optics
(210.4770) Optical data storage : Optical recording
(240.6670) Optics at surfaces : Surface photochemistry
(250.0250) Optoelectronics : Optoelectronics
Nelson V. Tabiryan and Cesare Umeton, "Surface-activated photorefractivity and electro-optic phenomena in liquid crystals," J. Opt. Soc. Am. B 15, 1912-1917 (1998)