Conversion of singular beams in free space: high-effective optical traps

Earlier investigations have shown that ordinary cover glasses for microscopes have small areas near a plate edge with a sharp surface profile that transform an initial fundamental Gaussian beam into a steady singular beam with the central zero at its axis. We have called such a glass area an optical vortex trap. In this paper, we study experimentally these singular beams in view of the optical traps of large microparticles in the near-IR spectrum area and discuss capture-particle theory in relation to such singular beams.