Optical manipulation of biological particles using LP21 mode in fiber.

We demonstrate the optical manipulation of biological particles using a low-order LP₂₁ fiber mode. The focused four-lobed LP₂₁ mode distribution was theoretically and experimentally found to be effective in optical tweezer applications, including selective cellular pick-up, pairing, grouping or separation, as well as rotation of cell dimers and clusters. Our proposed theoretical model estimates both the translational dragging force and rotational torque in good accordance with experimental data. With a simple all-fiber configuration, and low peak irradiation to target bioparticles, the proposed LP₂₁ ‘optical chuck’ system has great application potential in biological test systems. [ABSTRACT FROM AUTHOR]