Related Experiment Video
Updated: Sep 30, 2025
13:44
Simulation, Fabrication and Characterization of THz Metamaterial Absorbers
Published on: December 27, 2012
15.5K
Incident-angle-insensitive toroidal metamaterial
Optics Express
|March 18, 2022
Summary
This study demonstrates an asymmetric double-disk metamaterial with stable toroidal dipole resonance, even at wide incident angles. This offers enhanced local field confinement for optical device applications.
Area of Science:
- Metamaterials
- Plasmonics
- Nanophotonics
Background:
- Toroidal dipole resonance is crucial for advanced optical devices.
- Achieving stable resonance across various incident angles remains a challenge.
- Asymmetric nanostructures offer tunable electromagnetic responses.
Purpose of the Study:
- To investigate incident-angle-insensitive toroidal dipole resonance in an asymmetric double-disk metamaterial.
- To explore the local field confinement properties of the designed metastructure.
- To analyze the influence of structural parameters on toroidal dipole resonance.
Main Methods:
- Numerical simulations were performed in the near-infrared band.
- The response of the metamaterial was analyzed for incident angles from 0° to 90°.
- The dependence of resonance on radial asymmetry and gap distance was studied.
Main Results:
- The asymmetric double-disk metamaterial exhibited stable toroidal dipole resonance irrespective of incident angle (0°–90°).
- Excellent local field confinement was achieved.
- A wide polarization angle (up to 70°) for dominant toroidal dipole resonance was observed under normal incidence.
- Structural optimization maximized the local electric field amplitude.
Conclusions:
- The developed metastructure provides robust toroidal dipole resonance, overcoming angle sensitivity limitations.
- The findings enhance the understanding of toroidal moments and their applications.
- This research offers significant potential for developing novel optical devices.
Related Concept Videos
01:27Toroids
3.1K
A toroid is a closely wound donut-shaped coil constructed using a single conducting wire. In general, it is assumed that a toriod consists of multiple circular loops perpendicular to its axis.
When connected to a supply, the magnetic field generated in the toroid has field lines circular and concentric to its axis. Conventionally, the direction of this magnetic field is expressed using the right-hand rule. If the fingers of the right hand curl in the current direction, the thumb...
When connected to a supply, the magnetic field generated in the toroid has field lines circular and concentric to its axis. Conventionally, the direction of this magnetic field is expressed using the right-hand rule. If the fingers of the right hand curl in the current direction, the thumb...
3.1K
01:28Magnetostatic Boundary Conditions
1.2K
An electric field suffers a discontinuity at a surface charge. Similarly, a magnetic field is discontinuous at a surface current. The perpendicular component of a magnetic field is continuous across the interface of two magnetic mediums. In contrast, its parallel component, perpendicular to the current, is discontinuous by the amount equal to the product of the vacuum permeability and the surface current. Like the scalar potential in electrostatics, the vector potential is also continuous...
1.2K
01:13Torque On A Current Loop In A Magnetic Field
4.8K
The most common application of magnetic force on current-carrying wires is in electric motors. These consist of loops of wire, which are placed between the magnets with a magnetic field. When current flows through the loops, the magnetic field applies torque, which causes the shaft to rotate, thus converting electrical energy to mechanical energy.
Consider a rectangular current-carrying loop containing N turns of wire, placed in a uniform magnetic field. The net force on a current-carrying loop...
Consider a rectangular current-carrying loop containing N turns of wire, placed in a uniform magnetic field. The net force on a current-carrying loop...
4.8K
01:26Diamagnetism
2.5K
Materials consisting of paired electrons have zero net magnetic moments. However, when these materials are placed under an external magnetic field, the moments opposite to the field are induced. Such materials are called diamagnets. Diamagnetism is the response of the diamagnets when placed in an external magnetic field.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
2.5K
01:15Unsymmetric Bending - Angle of Neutral Axis
495
Unsymmetrical bending occurs when a structural member is subjected to bending moments in a plane that does not align with the member's principal axes. This scenario typically arises in beams and other structural components when loads are applied at non-ideal angles, introducing complexities in stress analysis.
When a bending moment is applied at an angle θ concerning the vertical axis of a symmetrical member, it can be resolved into components along the member's principal...
When a bending moment is applied at an angle θ concerning the vertical axis of a symmetrical member, it can be resolved into components along the member's principal...
495
01:24Potential Due to a Magnetized Object
365
Magnetic dipoles in magnetic materials are aligned when placed under an external magnetic field. For paramagnets and ferromagnets, dipole alignment occurs in the direction of the magnetic field. However, the dipoles align opposite to the field in the case of diamagnets. This state of magnetic polarization due to the external field is called magnetization. Magnetization is defined as the dipole moment per unit volume. It plays a similar role to polarization in electrostatics.
The vector...
The vector...
365