title: Dual-mode control of light by two-dimensional periodic structures realized in liquid-crystalline composite materials.
abstract: We report on the realization of a 2D refractive structure consisting of a polymer-liquid-crystal polymer slice grid. Nematic liquid crystal microdomains are confined inside well-sculptured elliptical cavities; experimental investigation shows that the liquid crystal director lies in the plane of the structure and its orientation follows a preferred direction. The sample exhibits both an electro-optical and an all-optical response owing to a small percentage of photosensitive azo dye included in the structure. A double external control of the two-dimensional grating efficiency can indeed be operated either by an optical pump beam or by the standard technique of applying a suitable external voltage to the sample.
authors: LICRYL (Liquid Crystals Laboratory, Institute for Chemical Physics Processes-CNR), Centre of Excellence for the Study of Innovative Functional Materials and Department of Physics, University of Calabria, 87036 Arcavacata di Rende, Italy. luciano.desio@fis.unical.it
authors: Luciano
authors: L
authors: De Sio
authors: Cesare
authors: C
authors: Umeton