Evanescent field interferometric optical tweezers with rotational symmetric patterns

摘要

A simple configuration to create optical lattices with N-fold rotational symmetry using the interference of N evanescent fields is proposed. The potential energy of a Rayleigh particle in the generated patterns (optical lattices) is investigated. The results show that by adjusting the relative phases and polarization states of the incident beams, an enormous range of optical lattices can be obtained. When the number of interfering beams is increased, circular spots beyond the diffraction limit can be created. For s-polarization, the intensity landscape has a dark-centered distribution at the origin encircled by a very small bright circular ring whose radius is 120 nm. This intensity distribution acts as a hollow beam and can be used for efficient trapping of low-index particles. We believe that the resulting lattices can find applications in the arrangement of particles, creation of optical lattices, and efficient trapping of very small Rayleigh particles. (C) 2017 Optical Society of America