Experimental demonstration of cylindrical vector spatiotemporal optical vortex

Jian Chen,Andy Chong,Chenhao Wan,Qiwen Zhan

doi:10.1515/nanoph-2021-0427

Abstract

Abstract We experimentally generate cylindrically polarized wavepackets with transverse orbital angular momentum, demonstrating the coexistence of spatiotemporal optical vortex with spatial polarization singularity. The results in this paper extend the study of spatiotemporal wavepackets to a broader scope, paving the way for its applications in various areas such as light–matter interaction, optical tweezers, spatiotemporal spin–orbit angular momentum coupling, etc.

Highlights

Optical singularities are zero intensity points within a light field with undefined physical quantities, including scalar singularity arising from undefined phase and vector singularity arising from undefined state of polarization [1]
The results in this paper extend the study of spatiotemporal wavepackets to a broader scope, paving the way for its applications in various areas such as light–matter interaction, optical tweezers, spatiotemporal spin–orbit angular momentum coupling, etc
Chen et al.: Cylindrically polarized spatiotemporal optical vortex characterized to reveal the conservation of transverse orbital angular momentum (OAM), during which the topological charge of the fundamental wavepacket is doubled along with the optical frequency [23]

Summary

Introduction

Optical singularities are zero intensity points within a light field with undefined physical quantities, including scalar singularity arising from undefined phase and vector singularity arising from undefined state of polarization [1]. Chen et al.: Cylindrically polarized spatiotemporal optical vortex characterized to reveal the conservation of transverse OAM, during which the topological charge of the fundamental wavepacket is doubled along with the optical frequency [23] All these works are limited to the scalar singularities contained within the STOV wavepackets. Cylindrical vector beams are generated by the combination of an array of linearly polarized beams, in which each beam has sub-aperture and controllable polarization Their focusing properties have been analyzed and utilized to tailor the distribution of the focused field [26]. The inherent mathematical non-separability of spatiotemporally structured light makes it a natural candidate for the forefront of entanglement studies [33, 34] Despite these inspiring theoretical works, as far as we know, there have been no reports on cylindrical vector spatiotemporal optical vortex either theoretically or experimentally. The vectorial STOV may find applications in light–matter interaction, optical tweezers, spatiotemporal spin–orbit angular momentum coupling, etc

Principle and experimental setup

Results

Conclusions