The interaction between structured light beams possessing optical angular momentum and small particles promises new opportunities for optical manipulation, such as the generation of light-induced torque and rotation of objects. However, so far, studies have largely centred on nanoscale particles. Here we report the observation and measurement of the transfer of transverse angular momentum to birefringent spherical vaterite particles several wavelengths in size. We outline the physics behind the beam used to control the particles, perform quantitative measurements of the transverse spin angular momentum transfer and demonstrate the generation of fluid flow around multiple rotation axes. The findings show that light can impart controllable rotational degrees of freedom to microparticles. In the future, the approach may prove useful for investigating the dynamics of complex fluids in three dimensions, studying the shear force on cell monolayers or cooling an optically trapped particle to the quantum ground state.

具有光学角动量的结构光束与小粒子之间的相互作用为光学操纵提供了新的机会，例如产生光致扭矩和物体旋转。然而，到目前为止，研究主要集中在纳米级粒子上。在这里，我们报告了横向角动量转移到几个波长大小的双折射球形球霰石颗粒的观察和测量。我们概述了用于控制粒子的光束背后的物理特性，对横向自旋角动量传递进行定量测量，并展示了围绕多个旋转轴产生的流体流动。研究结果表明，光可以赋予微粒可控的旋转自由度。在将来，