Related Experiment Video
Updated: Jul 4, 2025
13:44
Simulation, Fabrication and Characterization of THz Metamaterial Absorbers
Published on: December 27, 2012
15.4K
Coupling-Based Multiple Bound States in the Continuum and Grating-Assisted Permittivity Retrieval in the Terahertz
Zijian Cui1, Yue Wang1, Guangcheng Sun1
1Key Laboratory of Ultrafast Photoelectric Technology and Terahertz Science in Shaanxi, Xi'an University of Technology, 710048 Xi'an, China.
ACS Applied Materials & Interfaces
|February 1, 2024
Summary
Terahertz metasurfaces supporting bound states in the continuum (BICs) enable high-Q resonance. This study demonstrates multiple BICs with tunable symmetries in THz metasurfaces, paving the way for advanced biosensing applications.
Area of Science:
- Metasurfaces and Nanophotonics
- Terahertz Technology
- Resonant Phenomena
Background:
- Terahertz (THz) metasurfaces offer high Q-factor resonances, making them suitable for advanced applications.
- Bound states in the continuum (BICs) are crucial for achieving these high-Q resonances.
Purpose of the Study:
- To experimentally demonstrate multiple BICs with varying resonance symmetries in THz metasurfaces.
- To explore the tunability of quasi-BIC resonance through mode coupling and environmental changes.
- To showcase the application of these metasurfaces in biosensing.
Main Methods:
- Fabrication of THz metasurfaces using 2x2 split ring resonator (SRR) metamolecules.
- Tuning resonance frequencies and symmetries by adjusting SRR gap angles and lattice arrangements.
- Utilizing permittivity variations and microfluidic chips for sensing applications.
Main Results:
- Demonstration of multiple quasi-BICs with different symmetries simultaneously achieved in a single metasurface.
- Tunable quasi-BIC resonance by altering SRR gap angles and dielectric environment permittivity.
- Successful sensing of glucose solution concentration using the metasurface integrated with a microfluidic chip.
Conclusions:
- The study presents a viable strategy for achieving tunable quasi-BIC resonance in manufactured metasurfaces.
- The developed metasurfaces show significant potential for spectral analysis of biochemical analytes.
- This work advances the application of THz metasurfaces in sensitive detection and diagnostics.
Related Concept Videos
01:27¹H NMR: Long-Range Coupling
1.7K
The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
1.7K
01:08Spin–Spin Coupling Constant: Overview
924
In bromoethane, the three methyl protons are coupled to the two methylene protons that are three bonds away. In accordance with the n+1 rule, the signal from the methyl protons is split into three peaks with 1:2:1 relative intensities. The methylene protons appear as a quartet, with the relative intensities of 1:3:3:1.
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
924
01:12Double Resonance Techniques: Overview
210
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
Spin decoupling is usually achieved by...
210
01:26Susceptibility, Permittivity and Dielectric Constant
1.6K
When placed in an external electric field, a dielectric material gets polarized. The charge density in the dielectric material is given by the sum of the bound and free charge densities, while the total charge density can also be written in terms of the total electric field. The bound charge density can be measured in terms of polarization, leading to the relationship between electric displacement and polarization.
1.6K
01:13¹H NMR: Complex Splitting
1.3K
A proton M that is coupled to a proton X results in doublet signals for M. However, NMR-active nuclei can be simultaneously coupled to more than one nonequivalent nucleus. When M is coupled to a second proton A, such as in styrene oxide, each peak in the doublet is split into another doublet.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
1.3K
01:28Standing Waves in a Cavity
923
A household microwave and lasers are examples of standing electromagnetic waves in a cavity. When two conducting metal plates are placed parallel at the nodal planes, it creates a cavity where standing waves are formed. The cavity between the two planes is analogous to a stretched string held at the points x = 0 and x = L. Here, the distance 'L' between the two planes must be an integer multiple of half of the wavelength. The wavelengths that satisfy this condition are given by:
923