Theoretical simulation of Gaussian beam interferometric optical tweezers with symmetrical construction

Abstract

Multi-beam optical tweezers can be very effective and suitable for creating optical lattices and dexterous manipulation of the microscopic world. In an earlier work, a symmetrical multi-beam optical tweezers setup was proposed and theoretically investigated. In that study, however, we assumed that the incident beams were plane waves, and a plane wave cannot exist in real situations. The main aim of this paper is to investigate multi-beam optical tweezers under the realistic condition of using the Gaussian beams. The effects of changing the polarization state and the number of incident beams on potential landscapes are investigated. A comparison between the Gaussian beam and plane wave lattices is also performed. The results show that in the case of p-polarization, a very small spot (a sub-λ spot) can be achieved by increasing the number of incident beams. However, for s-polarized incident beams instead of a bright center, a dark center intensity distribution is obtained. The lattices constructed by the interference of the Gaussian beams have deeper traps in the central region compared to the plane wave lattices.