Liquid crystals: defects dictated

The new mechanism of writing stable particle molecular architectures in a chiral-nematic liquid crystal (LC) using a vortex laser beam has the potential to create new applications in liquid-crystal photonics. The new mechanism involves the use of laser light to manipulate the local molecular order of the LC resulting in the formation of unique liquid-confined quasiparticles with toroidal geometries. The new methodology was developed for forming defect structures at predetermined positions and with an well-controlled director pattern. Chiral-nematic LC molecules that are characterized by an asymmetric center in the molecule organize themselves by following a helicoidal director alignment under non-restricted conditions. A cell construct consisting of glass plates coated with a homeotropic aligning polyimide layer filled with LC materials has been developed to over such challenges