Generation of perfect vortex and vector beams based on Pancharatnam-Berry phase elements

Yachao Liu,Yougang Ke,Hailu Luo,Junxiao Zhou,Dianyuan Fan,Yuanyuan Liu,Shuangchun Wen

doi:10.1038/srep44096

Abstract

Perfect vortex beams are the orbital angular momentum (OAM)-carrying beams with fixed annular intensities, which provide a better source of OAM than traditional Laguerre-Gaussian beams. However, ordinary schemes to obtain the perfect vortex beams are usually bulky and unstable. We demonstrate here a novel generation scheme by designing planar Pancharatnam-Berry (PB) phase elements to replace all the elements required. Different from the conventional approaches based on reflective or refractive elements, PB phase elements can dramatically reduce the occupying volume of system. Moreover, the PB phase element scheme is easily developed to produce the perfect vector beams. Therefore, our scheme may provide prominent vortex and vector sources for integrated optical communication and micromanipulation systems.

Highlights

Orbital angular momentum (OAM) has been identified as a useful degree of freedom for enhancing the information carrying capacity of photon because of its unlimited dimensions[1], and has been found to have broad applications in optical manipulation and metrology due to the singularities in phase and intensity[2]
Perfect vortex beams are firstly considered as an ideal model of vortex beams with constant intensity distribution which doesn’t depend on its topological charge[3]
By using the PB phase elements designed above, Bessel Gaussian (BG) beams and Perfect vortex (PV) beams were produced in our experiments

Summary

Introduction

Orbital angular momentum (OAM) has been identified as a useful degree of freedom for enhancing the information carrying capacity of photon because of its unlimited dimensions[1], and has been found to have broad applications in optical manipulation and metrology due to the singularities in phase and intensity[2]. The non-diffraction property of PV beams scattering field shows the potential use in imaging and cryptography[13] Most of these methods are dependent on cumbrous reflective devices or bulky refractive devices to produce PV beams, which undoubtedly limits the application of PV beams in miniaturized optical systems and in fiber communications. PB phase elements including optical lens[18], vortex beam generators[19,20,21], hologram devices[22], mode transformer[23], and OAM multiplexer[24] have been realized up to now. Our scheme is developed to generate the perfect vector beams, which possesses the fixed annular intensity but is endowed with azimuthally varying polarizations

Methods

Results

Conclusion