Optical trapping gets structure: Structured light for advanced optical manipulation

Abstract

The pace of innovations in the field of optical trapping has ramped up in the past couple of years. The implementation of structured light, leading to groundbreaking inventions such as high-resolution microscopy or optical communication, has unveiled the unexplored potential for optical trapping. Advancing from a single Gaussian light field as trapping potential, optical tweezers have gotten more and more structure; innovative trapping landscapes have been developed, starting from multiple traps realized by holographic optical tweezers, via complex scalar light fields sculpted in amplitude and phase, up to polarization-structured and highly confined vectorial beams. In this article, we provide a timely overview on recent advances in advanced optical trapping and discuss future perspectives given by the combination of optical manipulation with the emerging field of structured light.

Symmetry and Quantum Features in Optical Vortices

“…There are highly interesting optical communication opportunities [157,158], with much of the current focus being the challenge of propagation through scattering or turbulent media [159][160][161]. Meanwhile, directly exploiting the orbital angular momentum of vortex beams finds microscale optomechanical applications in microparticle sorting [162], non-contact motorized lab-on-a-chip fluidics [163,164], and confined space rheology [165], while the application of vortex beams in the field of nanolithography has been shown to afford new top-down methods for directly fabricating chiral nanostructures [32,166]. The chirality intrinsically associated with such beams is of further interest for the additional dimension it can offer as a spectroscopic tool, where it is used as a probe of media ranging from chiral compounds [25,119], to plasmonic, nano-and metamaterials [34,167,168], and magnetic media [169], and in studies on free atoms [170,171].…”

Micro-/Nano-Structures Fabricated by Laser Technologies for Optoelectronic Devices

“…Inspired by the moth-eye structure, the reflectivity is reduced by introducing micro-/nano-structures. Mainly, the light will be internally reflected many times inside the structure to form a “light trap” ( Zhang et al, 2020a ; Otte and Denz, 2020 ; Yang et al, 2021 ). As a result, the existence of micro-/nano-structures can improve the light absorption capacity of the optoelectronic device.…”

Optical trapping with structured light: a review

“…Thus far, structured light beams with customized phase and amplitude have been successfully applied to drive the optical transport of particles in 3D trajectories by exerting optical forces arising from high intensity and phase gradients. Recently, there are several excellent review articles on this topic, [27][28][29][30][31][32][33] including optical pulling force, 28 optical transport of small particles, 29 optomechanics with levitated particles, 30 acoustic and optical trapping for biomedical research, 31 and so on. 32 More recently, advanced optical manipulation using structured light was reviewed, 33 which focused on the manipulation of transparent dielectric particles.…”