Theoretical Study on Generation of Multidimensional Focused and Vector Vortex Beams via All-Dielectric Spin-Multiplexed Metasurface.

Zhongchao Wei,Kuangling Guo,Yue Liu,Yuhan Hong,Li Chen,Chengxin Zhou,Xiaoyi Wang,Xiangbo Yang,Hongzhan Liu

doi:10.3390/nano12040580

Abstract

The optical vortex (OV) beams characterized by orbital angular momentum (OAM) possess ubiquitous applications in optical communication and nanoparticle manipulation. Particularly, the vortex vector beams are important in classical physics and quantum sciences. Here, based on an all-dielectric transmission metasurface platform, we demonstrate a spin-multiplexed metadevice combining propagation phase and Pancharatnam–Berry (PB) phase. By utilizing a phase-only modulation method, the metadevice can generate spin-dependent and multidimensional focused optical vortex (FOV) under the orthogonally circularly polarized incident light, and it can successfully realize the multiplexed of the above-mentioned FOVs for linearly polarized light. Meanwhile, the superposition of multiple OAM states can also produce vector vortex beams with different modes. Additionally, the evolution process of the electric field intensity profile is presented after the resultant vector vortex beams through a horizontal linear polarization. This work paves an innovative way for generating structured beams, and it provides promising opportunities for advanced applications in optical data storage, optical micromanipulation, and data communication.

Highlights

Optical vortex (OV) refers to a laser beam carrying the orbital angular momentum (OAM), which is prominently characterized by a helical phase front and doughnut-shaped intensity profile in the plane orthogonal to the light propagation [1]
Λ where λ is the working wavelength, fL and fR are the focal lengths of left-handed circularly polarized (LCP) and right-handed circularly polarized (RCP) incident light along the z direction, and lm and ln represent the topological charges of focused optical vortex (FOV) for LCP and RCP light, respectively
It can be seen that the FOV is located at z = 12.4 μm, which is close to the preset value

Summary

Introduction

Optical vortex (OV) refers to a laser beam carrying the orbital angular momentum (OAM), which is prominently characterized by a helical phase front and doughnut-shaped intensity profile in the plane orthogonal to the light propagation [1]. It can be expressed by a transverse phase structure of exp(ilφ), where l is the topological charge as any integer and φ is the azimuthal angle. Vector vortex beam can be realized by the superposition of multiple OAM states [9] and plays a vital role in optical capture [10], laser processing [11], and optical communication [12]. The vector vortex beam can be gained by the superposition of multiple spatial beams, phase plates, and spatial light

Methods

Results

Conclusion