Nondiffractive three-dimensional polarization features of optical vortex beams

Afanasev, Andrei; Kingsley-Smith, Jack J.; Rodríguez-Fortuño, Francisco J.; Zayats, Anatoly V.

doi:10.1117/1.apn.2.2.026001

Cited by 11 publications

(6 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hence, p z = 1 is dominated by right-circular components, while p zz = 1 is dominated by transverse components. For the optical vortex beams, a similar effect was demonstrated to follow from Maxwell's equations [26].…”

Section: Polarization Parameters Of Atomic-array Radiationmentioning

confidence: 67%

Topology and Polarization of Optical Vortex Fields from Atomic Phased Arrays

Wang

Afanasev

2023

Applied Sciences

Self Cite

View full text Add to dashboard Cite

We developed a theoretical formalism for the generation of optical vortices by phased arrays of atoms. Using the Jacobi–Anger expansion, we demonstrated the resulting field topology and determined the least number of individual atoms necessary for the generation of vortices with a given topological charge. Vector vortices were considered, taking into account both the spin and orbital angular momenta of electromagnetic fields. It was found for the vortex field that, in the far field limit, the spatial variation in spin-density matrix parameters—orientation and alignment—is independent of the distance to the radiation source.

show abstract

Section: Polarization Parameters Of Atomic-array Radiationmentioning

confidence: 67%

Topology and Polarization of Optical Vortex Fields from Atomic Phased Arrays

Wang

Afanasev

2023

Applied Sciences

Self Cite

View full text Add to dashboard Cite

show abstract

“…We believe that this will prove a valuable tool for many researchers and so provide an open-source software package called BEAMS (Beams scattering through Electromagnetic Axisymmetric Multilayers and Structures) where this post-processing method is implemented in MATLAB and provided at reference [76]. We have made use of this package in recent works to simulate vortex beams in free space to study their polarisation properties [77] as well as in optical traps with Gaussian beams interacting with nanorod particles [78], where we were able to compute in a matter of minutes (hours if including finite element method (FEM) simulation time) a full force map that could have otherwise taken us weeks, and which agreed with experimental measurements. These serve as clear examples of the usefulness and robustness of this method in modern research problems.…”

Section: Discussionmentioning

confidence: 99%

Efficient post-processing of electromagnetic plane wave simulations to model arbitrary structured beams incident on axisymmetric structures

Kingsley-Smith,

Rodríguez-Fortuño

2023

New J. Phys.

View full text Add to dashboard Cite

The study of an optical beam interacting with material structures is a fundamental of nanophotonics. Computational electromagnetic solvers facilitate the rapid calculation of the scattering from material structures with arbitrary geometry and complexity, but have limited eﬃciency when employing structured excitation ﬁelds. We have developed a post-processing method and package that can eﬃciently calculate the full three-dimensional electric and magnetic ﬁelds for any optical beam incident on a particle or structure with at least one axis of continuous rotational symmetry, called an axisymmetric body (such as a sphere, cylinder, cone, torus or surface). Provided an initial batch of plane wave simulations is computed, this open-source package combines data from computational electromagnetic solvers in a post-processing fashion using the angular spectrum representation to create arbitrarily structured beams, including vector vortex beams. Any and all possible incident beams can be generated from the initial batch of plane wave simulations, without the need for further simulations. This allows for eﬃciently performing parameter sweeps such as changing the angle of illumination or translating the particle position relative to the beam, all in post-processing, with no need for additional time-consuming simulations. We demonstrate some applications by numerically calculating optical force and torque maps for a spherical plasmonic nanoparticle in a tightly focused Gaussian beam, a plasmonic nanocone in an azimuthally polarised beam and compute the ﬁelds of a non-paraxial Laguerre-Gaussian vortex beam reﬂecting on a multilayered surface. We believe this package, called BEAMS, is a valuable tool for rapidly quantifying electromagnetic systems that are beyond traditional analytical methods.

show abstract

“…By extracting these features, the appearance of the motion posture contour of human motion targets can be described and represented, and the shape, posture, rotation and other features of the targets can be captured. The moving image sequence with this optical feature can show the characteristics of constant translation, constant scale, and constant selection [9], which enables better results to be achieved when matching moving human targets from various perspectives. This feature also can identify the target object, which is determined by selecting the extreme points of the Gaussian difference function in the scale space.…”

Section: ) Obtaining Feature Extraction Map Of Moving Human Objects B...mentioning

confidence: 99%

Reconstruction of 3D Non-Rigid Moving Human Targets Based on Reliable Estimation of Contour Deformation Degree

Zhang,

Baza,

Alshahrani

2024

IEEE Access

View full text Add to dashboard Cite

The human body is a typical non-rigid object, and its 3D reconstruction is a classic problem in the field of computer vision. Due to the inherent complexity and dynamism of the human body, it is not suitable for existing non-rigid 3D motion reconstruction algorithms that assume that the number of shape bases of non-rigid bodies is known. The number of shape bases is very important for 3D reconstruction methods. If the number of shape bases is estimated incorrectly in contour deformation estimation, it can lead to unreliable or even complete failure of the reconstruction algorithm. Therefore, this paper designs a 3D non-rigid motion human object reconstruction algorithm based on reliable estimation of contour deformation degree. This algorithm leverage Scale Invariant Feature Transform (SIFT) to obtain non-rigid moving human target features. Firstly, the contour appearance model of the moving human sequence is used to extract the contour feature sequence, which is preprocessed based on the contour appearance depth feature; Furthermore, the deformation degree of the contour is reconstructed and the calculation process of the number of shape bases was optimized, which is no longer simply defined as known. This method optimizes and solves the problem of missing data, improves the reliability of estimating the degree of contour deformation, and completes target reconstruction. The experimental results show that the threedimensional reconstruction algorithm can accurately reconstruct the changes in the movements of athletes' shots; The accuracy of 3D reconstruction can reach 95.98%; Moreover, PSNR, SSIM, and MSE indexes performed well with smaller fluctuation range, and the distribution of three-dimensional reconstructed scattering points is very close to the three-dimensional position distribution of real scattering points, and the three-dimensional reconstruction effect is good with strong reliability.

show abstract

Nondiffractive three-dimensional polarization features of optical vortex beams

Cited by 11 publications

References 26 publications

Topology and Polarization of Optical Vortex Fields from Atomic Phased Arrays

Topology and Polarization of Optical Vortex Fields from Atomic Phased Arrays

Efficient post-processing of electromagnetic plane wave simulations to model arbitrary structured beams incident on axisymmetric structures

Reconstruction of 3D Non-Rigid Moving Human Targets Based on Reliable Estimation of Contour Deformation Degree

Contact Info

Product

Resources

About