Circularly symmetric frozen waves and their optical forces in optical tweezers using a ray optics approach

Abstract

In this work we analyze, in the ray optics regime, the optical forces exerted on micro-sized dielectric spheres due to optical beams created as suitable discrete superpositions of scalar and vector Bessel beams — also known as frozen waves, thus envisioning applications in optical tweezers. Scalar frozen waves have been recently and theoretically introduced as auxiliary optical fields in the trapping and manipulation of neutral particles paper in both the Rayleigh (dipole) and the Mie regimes, the latter demanding a full electromagnetic treatment. Here, the extension of previous studies is twofold in the sense that we perform investigations both in the ray optics regime, which has only been previously considered in terms of simplistic models, and in terms of a vector approach which allows us to go beyond the paraxial approximation.