Optical rotation and cell control based on the LP21 mode and a tapered microcavity optical waveguide

This paper innovatively proposes a single-fiber optical tweezers probe based on a tapered microcavity optical waveguide. This design leverages the dual characteristics of the fiber LP21 mode to achieve dual-mode, high-precision rotational manipulation of cells: on one hand, by precisely controlling the fiber twist angle, the LP21 mode spot can be rotated regularly, driving cells trapped by the optical tweezers on the outer wall of the tapered microtube to undergo controlled "orbital rotation" along the tube wall in the y-z plane; on the other hand, by adjusting the fiber stretching degree to modulate the LP21 mode spot energy distribution, the multi-physical fields (including optical, flow fields, etc.) at the microtube port are altered, inducing an optically induced vortex to drive cells at the port to perform controlled "spin rotation" in the x-y plane. This single-fiber technique, integrating both "orbital" and "spin" rotational manipulation, provides a reliable tool for cutting-edge fields urgently requiring precise rotation tools, such as biological motor research, artificial erythrocyte preparation, and polarized cell behavior analysis, holding broad application prospects in chemical synthesis, biomedicine, and fundamental research.