Enhanced optoelastic interaction range in liquid crystals with negative dielectric anisotropy

Francesco Simoni (1, 2) , S. Lalli (1, 2) , Liana Lucchetti (1, 2) , L. Criante (3) , Etienne Brasselet (4)

1 CNISM - Consorzio Nazionale Interuniversitario per la Struttura della Materia
2 Dipartimento di Scienze e Ingegneria della Materia, dell'Ambiente ed Urbanistica
3 Center for Nano Science and Technology@PoliMi
4 LOMA - Laboratoire Ondes et Matière d'Aquitaine

We demonstrate that the long-range interaction between surface-functionalized microparticles immersed a nematic liquid crystal--a "nematic colloid"--and a laser-induced "ghost colloid" can be enhanced by a low-voltage quasistatic electric field when the nematic mesophase has a negative dielectric anisotropy. The optoelastic trapping distance is shown to be enhanced by a factor up to 2.5 in presence of an electric field. Experimental data are quantitatively described with a theoretical model accounting for the spatial overlap between the orientational distortions around the microparticle and those induced by the trapping light beam itself.

Domaines: Optique [physics.optics]

Francesco Simoni, S. Lalli, Liana Lucchetti, L. Criante, Etienne Brasselet. Enhanced optoelastic interaction range in liquid crystals with negative dielectric anisotropy. Applied Physics Letters, 2014, 104 (1), pp.011112 (1-4). ⟨10.1063/1.4861473⟩. ⟨hal-00927719⟩