title: Optical trapping induced by reorientational nonlocal effects in nematic liquid crystals.
abstract: We report a detailed analysis of optical trapping of low index particles in liquid crystals under experimental conditions that prevent the effect of conventional trapping originated by optical gradient forces. The observation of stable, long-range trapping shows that this phenomenon in liquid crystals is regulated by a completely different mechanism than in isotropic media. In particular, the role of the nonlocality of optical reorientation is highlighted by showing the dependence of the trapping force on the size of the reoriented area. A model based on the actual form of the Gaussian focused beam impinging on the liquid-crystalline medium in the trapping experiment is also reported, with good agreement with experimental data.
authors.affiliation: Dipartimento di Fisica e Ingegneria dei Materiali e del Territorio and CNISM, Università Politecnica delle Marche, via Brecce Bianche, I-60131 Ancona, Italy. l.lucchetti@univpm.it
authors.forename: L
authors.initials: L
authors.lastname: Lucchetti
authors.forename: L
authors.initials: L
authors.lastname: Criante
authors.forename: F
authors.initials: F
authors.lastname: Bracalente
authors.forename: F
authors.initials: F
authors.lastname: Aieta
authors.forename: F
authors.initials: F
authors.lastname: Simoni