Abstract

In this work we present a numerical evaluation of the forces in an optical tweezers system, for metallic nanoparticles in theRayleigh regime. Initially a Gaussian beam is described in the scalar approximation, and the forces it can apply on Rayleighdielectric and metallic particles are computed within the point-dipole approach. The method is then extended to dielectricand metallic Rayleigh particles in a Laguerre-Gaussian beam, i.e. a higher order beam that is increasingly used for opticaltrapping experiments. We discuss the limits of the approximation for the beam intensity by comparing the numerical resultswith the experimental measurements that can be found in literature.