Multifunctional Optical Vortex Beam Generator via Cross-Phase Based on Metasurface

Kuangling Guo,Hongzhan Liu,Yue Liu,Zhongchao Wei,Li Chen

doi:10.3390/nano12040653

Abstract

We propose a multifunctional optical vortex beam (OVB) generator via cross-phase based on a metasurface. Accordingly, we separately investigate the two different propagation characteristics of OVB modulated by the low-order cross-phase (LOCP) and the high-order cross-phase (HOCP) in a self-selected area. When LOCP modulation is added to OVB, topological charges can be measured for any order of OVB. Moreover, we achieve the rotation tunable performance successfully by adding the rotation component. Then, we realize the function of polygonal beam generation and singularities regulation with the HOCP. The order of the HOCP is exactly equal to the number of a polygon OVB’s sides. The waist radius and usable width of the beam lengthens as the distance of the self-selected area increases. When the conversion rate is doubled, the distance between singularities widens by about 0.5 μm. The proposed OVB generator provides a simple strategy for detecting the value of topological charges and achieving OVB shaping and singularity manipulation simultaneously. We hope this can open new horizons for promoting the development of photon manipulation, optical communication, and vortex beam modulation.

Highlights

As early as 1992, Allen et al [1] first discovered that in addition to the general spin angular momentum (SAM) [2], photons can carry orbital angular momentum (OAM).Optical vortex beam (OVB), with the phase factor exp(ilφ), is a special kind of beam carryingOAM of lhper photon, where l denotes the topological charges (TCs), which can be any integer, φ denotes the azimuthal angle, and his the Planck constant
We introduce the propagation characteristics of a metasurface controlled by low-order cross-phase (LOCP)
We have proved the different functions of the multifunctional OVB generator regulated by CP through simulation

Summary

Introduction

As early as 1992, Allen et al [1] first discovered that in addition to the general spin angular momentum (SAM) [2], photons can carry orbital angular momentum (OAM).Optical vortex beam (OVB), with the phase factor exp(ilφ), is a special kind of beam carryingOAM of lhper photon, where l denotes the topological charges (TCs), which can be any integer, φ denotes the azimuthal angle, and his the Planck constant. As early as 1992, Allen et al [1] first discovered that in addition to the general spin angular momentum (SAM) [2], photons can carry orbital angular momentum (OAM). Optical vortex beam (OVB), with the phase factor exp(ilφ), is a special kind of beam carrying. Due to the particularity of carrying OAM, more and more scholars started to study the generation of the OVB. The OAM carried by a single photon can theoretically carry an infinite amount of information [3]. In this way, since the OVB can extend the communication capability through strictly orthogonal channels of different

Methods

Results

Conclusion