Related Experiment Video
Updated: Jul 31, 2025
04:35
Preparation of Free-Surface Hyperbolic Water Vortices
Published on: July 28, 2023
2.7K
Metasurface-based perfect vortex beams with trigonometric-function topological charge for OAM manipulation.
Optics Letters
|May 1, 2023
Summary
Researchers generated perfect vortex beams (PVBs) with novel sine-function topological charge (TC) using metasurfaces. This innovation offers new possibilities for optical vortex manipulation and communication.
Area of Science:
- Optics and Photonics
- Metamaterials
- Optical Vortex Manipulation
Background:
- Topological charge (TC) defines the twist of optical vortex (OV) wavefronts, typically as a constant integer or fraction.
- Tailoring TC offers potential for advanced optical applications.
Purpose of the Study:
- To numerically demonstrate the generation of perfect vortex beams (PVBs) with a spatially varying, sine-function topological charge.
- To explore the potential of these novel PVBs for particle manipulation and optical communication.
Main Methods:
- Utilizing all-dielectric geometric metasurfaces with unit structures optimized as half-wave plates.
- Transforming topological charges into trigonometric functions of the azimuthal angle to tailor spiral phase distributions.
- Numerically calculating orbital angular momentum (OAM) and optical gradient force distributions.
Main Results:
- Successful generation of PVBs with sine-function TC.
- Demonstration of tailored spiral phase distributions.
- Analysis of OAM and optical gradient force distributions for particle manipulation.
Conclusions:
- The proposed method provides a novel approach for generating PVBs with spatially varying TC.
- These PVBs show promise for advanced OAM manipulation, information storage, and optical communication.
Related Concept Videos
01:10Angular Momentum: Single Particle
6.5K
Angular momentum is directed perpendicular to the plane of the rotation, and its magnitude depends on the choice of the origin. The perpendicular vector joining the linear momentum vector of an object to the origin is called the “lever arm.” If the lever arm and linear momentum are collinear, then the magnitude of the angular momentum is zero. Therefore, in this case, the object rotates about the origin such that it lies on the rim of the circumference defined by the lever arm...
6.5K
01:18Conservation of Angular Momentum: Application
11.3K
A system's total angular momentum remains constant if the net external torque acting on the system is zero. Examples of such systems include a freely spinning bicycle tire that slows over time due to torque arising from friction, or the slowing of Earth's rotation over millions of years due to frictional forces exerted on tidal deformations. However in the absence of a net external torque, the angular momentum remains conserved. The conservation of angular momentum principle requires a...
11.3K
01:11Angular Momentum about an Arbitrary Axis
229
Imagine a rigid body with a mass denoted as 'm', which has its center of mass at point G and is rotating around an inertial reference frame. The angular momentum at an arbitrary point P can be calculated by taking the cross product of the position vector and linear momentum vector for each individual mass element.
The velocity of a mass element comprises its translational velocity and the relative velocity instigated by the body's rotation. Substituting the velocity equation into...
The velocity of a mass element comprises its translational velocity and the relative velocity instigated by the body's rotation. Substituting the velocity equation into...
229
01:09Conservation of Angular Momentum
10.6K
A system's total angular momentum remains constant if the net external torque acting on the system is zero. Considering a system that consists of n tiny particles, the angular momentum of any tiny particle may change, but the system's total angular momentum would remain constant. The principle of conservation of angular momentum only considers the net external torque acting on the system. While there are internal forces exerted by different particles within the system that also produce...
10.6K
01:15Magnetic Vector Potential
711
In electrostatics, the electric field can be written as the negative gradient of the potential. In magnetostatics, the zero divergence of the magnetic field ensures that the magnetic field can be expressed as the curl of a vector potential. This potential is known as the magnetic vector potential.
Consider an ideal solenoid with n turns per unit length and radius R. If I is the current through the solenoid, the magnetic field inside the solenoid is expressed as the product of vacuum...
Consider an ideal solenoid with n turns per unit length and radius R. If I is the current through the solenoid, the magnetic field inside the solenoid is expressed as the product of vacuum...
711
01:28Symmetry in Maxwell's Equations
3.5K
Once the fields have been calculated using Maxwell's four equations, the Lorentz force equation gives the force that the fields exert on a charged particle moving with a certain velocity. The Lorentz force equation combines the force of the electric field and of the magnetic field on the moving charge. Maxwell's equations and the Lorentz force law together encompass all the laws of electricity and magnetism. The symmetry that Maxwell introduced into his mathematical framework may not be...
3.5K