Optical trapping of Rayleigh particles based on four-petal Gaussian vortex beams

The intensity distribution of four-petal Gaussian vortex (FPGV) beams through a focused optical system and the radiation force acting on a Rayleigh dielectric sphere is obtained based on the extended Huygens–Fresnel principle and the Rayleigh scattering theory. We mainly study the trapping of high and low refractive index Rayleigh particles by FPGV beams and the effect of the topological charge m on the radiation force. The results show that the specific distribution of the incident beam can be controlled by a reasonable choice of topological charge m. The multiple locations in a beam of light where particles of different refractive indices can be captured will be found. On the other hand, when m changes, the number of particles captured and the locations where they can be captured change accordingly. Therefore, the flexibility to simultaneously capture multiple Rayleigh particles with different refractive indices with a single beam at different locations in the focal plane can be achieved using the FPGV beam.