Generation of concentric perfect Poincar\xe9 beams

Zhongzheng Gu,Caojin Yuan,Yanran Zhang,Fengyan Gu,Shouping Nie,Shaotong Feng,Jun Ma,Da Yin

doi:10.1038/s41598-019-50705-z

Abstract

We theoretically propose and experimentally verify a method to generate new polycyclic beams, namely concentric perfect Poincaré beams (CPPBs), by using an encoded annular phase mask. The proposed beams consisting of multiple polarization structured fields can be simultaneously generated in one concentric mode, which are respectively mapped by fundamental Poincaré sphere (PS), high-order Poincaré sphere (HOPS), and hybrid-order Poincaré sphere (HyPS). Moreover, the ring radius, numbers and polarization orders of the CPPBs at arbitrary positions on arbitrary PS are independently controlled. This work enriches the mode distributions of perfect vortex and introduces a new polarization degree of freedom, which has the potential to implement more information beyond the orbital angular momentum multiplexing in optical communication.

Highlights

Optical vortex beams carrying orbital angular momentum have attracted considerable attention in many exciting fields such as optical communication[1,2,3,4,5], optical trapping[6,7], optical imaging[8], optical measurement[9,10], quantum information processing[11,12,13] and so on
To visually present the states of polarization and phase, the concentric beams which are of isotropic and anisotropic polarizations can be represented by a prominent geometry such as a fundamental PS25, a HOPS26,27 and a HyPS28, where the state of polarization can be described as a point on the surface of a unit sphere
States on fundamental Poincaré sphere (PS), high-order Poincaré sphere (HOPS), and hybrid-order Poincaré sphere (HyPS) are uniformly referred to Poincaré beams, which describe almost all polarization structured fields[29]

Summary

Introduction

Optical vortex beams carrying orbital angular momentum have attracted considerable attention in many exciting fields such as optical communication[1,2,3,4,5], optical trapping[6,7], optical imaging[8], optical measurement[9,10], quantum information processing[11,12,13] and so on. Panchanratnam-Berry phase method[18] and combined modulation method of geometric and dynamic phase[19] were proposed to flexibly generate perfect vector beams. Taking advantage of this property, Chen et al successfully utilized the perfect vortex beam to perform particle manipulation[20], following which its application has extended to the optical fiber communication field[21]. The degree of freedom of polarization, as an important parameter in OAM multiplexing technology, cannot be freely controlled, which limits the multiplexing capacity in optical communication. Due to the richness of polarization and OAM multiplexing of CPPBs, this method of generating CPPBs has the potential to greatly increase communication capacity

Methods

Results

Conclusion