Scalable generalized meta-spanners enabling parallel multitasking optical manipulation.

Abstract

Optical manipulation techniques offer exceptional contactless control but are fundamentally limited in their ability to perform parallel multitasking. To achieve high-density, versatile manipulation with subwavelength photonic devices, it is essential to sculpt light in multiple dimensions. Here, we overcome this challenge by introducing generalized optical meta-spanners (GOMSs) based on metasurfaces, which generate speckle-free, customizable optical vortices that suppress diffractive losses. As a result, several advanced functionalities are simultaneously achieved, including longitudinally varying manipulation and in-plane spanner arrays, which outperforms the same operations realized by conventional donut-shaped orbital flows. Furthermore, the particle dynamics are reconfigurable by simply switching the input and output polarizations, facilitating robust multichannel control. We experimentally validate our approach through the stable manipulation of both single particle and particle ensembles, demonstrating scalable multitasking stability for numerous simultaneous optical spanners, and advancing metadevices from wavefront sculptors to particle manipulators. We envision that the GOMS will catalyze innovations in cross-disciplinary fields such as targeted drug delivery and cell-level biomechanics.