Arrangement of Micro Dielectric Particles With Vector Vortex Beam Generated by Dual-Helical Dielectric Cone

Optical vortex is of great value in optical trapping, manipulating, and arranging. Here, we propose a dual-helical dielectric cone to generate a dual-vortex beam which can be used to manipulate and arrange dielectric microparticles in three-dimensional space. With the finite-difference time-domain simulation, we calculate the electromagnetic field intensity distribution, phase, and Poynting vector during the propagation of the dual-vortex beam, the optical force and optical torque on the microparticles in the range of dual-vortex beam is also considered. In the experiment, we use the phase mask projected on spatial light modulator to generate a dual-vortex beam, which can trap, manipulate, and arrange the fluorescent microparticles to a specific and stable shape, which is consistent with the results of our simulation calculations. The dual-vortex beam generated by the dual-helical dielectric cone provides a feasible method three-dimensional optical manipulation, which is significant in biophotonical researches.