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Updated: May 2, 2026

Capillary-based Centrifugal Microfluidic Device for Size-controllable Formation of Monodisperse Microdroplets
Published on: February 22, 2016
Controllable Microparticle Spinning via Light without Spin Angular Momentum
Yi-Jing Wu1, Pan-Pan Yu1, Yi-Fan Liu1
1Department of Optics and Optical Engineering, <a href="https://ror.org/04c4dkn09">University of Science and Technology of China</a>, Hefei 230026, China.
Abstract:
The spin angular momentum (SAM) of an elliptically or circularly polarized light beam can be transferred to matter to drive a spinning motion. It is counterintuitive to find that a light beam without SAM can also cause the spinning of microparticles. Here, we demonstrate controllable spinning of birefringent microparticles via a tightly focused radially polarized vortex beam that has no SAM prior to focusing. To this end, the orbital Hall effect is proposed to control the radial separation of two spin components in the focused field, and tunable transfer of local SAM to microparticles is achieved by manipulating the twisted wavefront of the source light. Our work broadens the perspectives for controllable exertion of optical torques via the spin-orbit interactions.
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