Tunable optical gradient force of radially polarized Lorentz-Gauss vortex beam by sine-azimuthal variation wavefront

Tunable optical gradient force distributions of radially polarized Lorentz-Gauss vortex beam by sine-azimuthal variation wavefront were investigated by vector diffraction theory, which shows that many interesting force patterns may appear, including "x" shape optical trap, twines "C" shape optical trap, crescent shape optical trap, and overlapping optical gradient force traps. And whole force distributions are symmetric about two coordinate axes for case of even number value of phase parameter, while only symmetric about one coordinate axis for odd number value of phase parameter. Effect of charge number of the optical vortex on force pattern evolution is more remarkable for lower phase parameter than that for higher. Force pattern is very sensitive to phase parameter, therefore, force pattern may be used to act as one kind of measurement method of phase parameter. (C) 2016 Elsevier GmbH. All rights reserved.