Optical binding: a scattering-mediated force arising in micro- and nanoscopic samples

This paper provides a detailed investigation of optical binding as a scattering mediated force arising in micro- and nanoscopic samples. We systematically study the interaction between pairs of trapped scatterers as a function of the experimental parameters for different sets of particles; this provides a set of equilibrium mutual distances between the small spheres, where the particles remain for relatively long times during their thermal-agitation-induced motion. These results help understanding the fundamentals of the short-range interaction between scatterers in a coherent light field: the basic, nonlinear force responsible for coherent self-organization and structuring of large ensembles of microspheres.