Abstract:
The discovery of orbital angular momentum (OAM) opens up a new way for the study of optical tweezers. However, the size and shape of biological cells cannot be exactly the same, when the beam with OAM manipulates the particles. So, the uneven velocity of the particles will lead to uncontrollable spacing between the particles when it carries out operations such as rotation. To solve the problem, a cycloid beam with rich regulation modes was proposed by using an arbitrary curve shaping technique and adding curvature control parameters to the traditional cycloid formula. The OAM and gradient force of the cycloid beam was theoretically analyzed, and the possibility of solving the problem was theoretically analyzed. Finally, the start and stop of particles in the process of motion were realized in the experiment, and the three particles were successfully manipulated to rotate at the same distance. The experimental results show that the error of the distance variation of the three particles during the whole rotation process can be maintained at the nanometer level. The work paves the way for future applications of light to capture and manipulate a variety of particles in other fields, particularly in the biological sciences.