Spectral amplitude modulation and dynamic near-field displaying of all-silicon terahertz metasurfaces supporting bound states in the continuum

2021 ◽  
Vol 119 (24) ◽  
pp. 241105
Author(s):  
Jitao Li ◽  
Jie Li ◽  
Chenglong Zheng ◽  
Zhen Yue ◽  
Dingyu Yang ◽  
...  
Keyword(s):  
Amplitude Modulation ◽  
Bound States ◽  
Near Field ◽  
Spectral Amplitude ◽  
The Continuum

scholarly journals Near-Field Excitation of Bound States in the Continuum in All-Dielectric Metasurfaces through a Coupled Electric/Magnetic Dipole Model

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 998
Author(s):  
Diego R. Abujetas ◽  
José A. Sánchez-Gil
Keyword(s):  
Magnetic Dipole ◽  
Density Of States ◽  
Bound States ◽  
Local Density ◽  
Near Field ◽  
Field Pattern ◽  
Local Density Of States ◽  
Optical Modes ◽  
Source Excitation ◽  
The Continuum

Resonant optical modes arising in all-dielectric metasurfaces have attracted much attention in recent years, especially when so-called bound states in the continuum (BICs) with diverging lifetimes are supported. With the aim of studying theoretically the emergence of BICs, we extend a coupled electric and magnetic dipole analytical formulation to deal with the proper metasurface Green function for the infinite lattice. Thereby, we show how to excite metasurface BICs, being able to address their near-field pattern through point-source excitation and their local density of states. We apply this formulation to fully characterize symmetry-protected BICs arising in all-dielectric metasurfaces made of Si nanospheres, revealing their near-field pattern and local density of states, and, thus, the mechanisms precluding their radiation into the continuum. This formulation provides, in turn, an insightful and fast tool to characterize BICs (and any other leaky/guided mode) near fields in all-dielectric (and also plasmonic) metasurfaces, which might be especially useful for the design of planar nanophotonic devices based on such resonant modes.

scholarly journals High Quality-Factor Dual-Band Fano Resonances Induced by Bound States in The Continuum Using A Planar Nanohole Slab

2021 ◽  
Author(s):  
Tian Sang ◽  
Qing Mi ◽  
Yao Pei ◽  
Chaoyu Yang ◽  
Shi Li ◽  
...  
Keyword(s):  
Bound States ◽  
Near Field ◽  
Dual Band ◽  
Q Factor ◽  
Fano Resonances ◽  
High Quality ◽  
Potential Applications ◽  
Q Factors ◽  
Symmetry Protected ◽  
The Continuum

Abstract In photonics, it is essential to achieve high quality (Q)-factor resonances to enhance light-mater interactions for improving performances of optical devices. Herein, we demonstrate that high Q-factor dual-band Fano resonances can be achieved by using a planar nanohole slab (PNS) based on the excitation of bound states in the continuum (BICs). By shrinking or expanding the tetramerized holes of the superlattice of the PNS, symmetry-protected BICs can be excited and the locations of Fano resonances as well as their Q-factors can be flexibly tuned. Physical mechanisms for the dual-band Fano resonances can be interpreted as the resonant couplings between the electric-toroidal dipoles or the magnetic-toroidal dipoles based on the far-field multiple decompositions and the near-field distributions of the superlattice. The dual-band Fano resonances of the PNS possess polarization independent feature, they can be survived even the geometric parameters of the PNS are significantly altered, making them more suitable for potential applications.

scholarly journals High-quality-factor dual-band Fano resonances induced by dual bound states in the continuum using a planar nanohole slab

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Qing Mi ◽  
Tian Sang ◽  
Yao Pei ◽  
Chaoyu Yang ◽  
Shi Li ◽  
...  
Keyword(s):  
Bound States ◽  
Near Field ◽  
Dual Band ◽  
Q Factor ◽  
Fano Resonances ◽  
High Quality ◽  
Dual Bound ◽  
Potential Applications ◽  
Q Factors ◽  
The Continuum

AbstractIn photonics, it is essential to achieve high-quality (Q)-factor resonances to improve optical devices’ performances. Herein, we demonstrate that high-Q-factor dual-band Fano resonances can be achieved by using a planar nanohole slab (PNS) based on the excitation of dual bound states in the continuum (BICs). By shrinking or expanding the tetramerized holes of the superlattice of the PNS, two symmetry-protected BICs can be induced to dual-band Fano resonances and their locations as well as their Q-factors can be flexibly tuned. Physical mechanisms for the dual-band Fano resonances can be interpreted as the resonant couplings between the electric toroidal dipoles or the magnetic toroidal dipoles based on the far-field multiple decompositions and the near-field distributions of the superlattice. The dual-band Fano resonances of the PNS possess polarization-independent feature, and they can be survived even when the geometric parameters of the PNS are significantly altered, making them more suitable for potential applications.

scholarly journals Manipulating Optical Scattering of Quasi-BIC in Dielectric Metasurface with Off-Center Hole

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 54
Author(s):  
Chaobiao Zhou ◽  
Tianyao Pu ◽  
Jing Huang ◽  
Menghui Fan ◽  
Lujun Huang
Keyword(s):  
Radiation Pattern ◽  
Bound States ◽  
Near Field ◽  
Research Work ◽  
Electric Quadrupole ◽  
Asymmetric Structure ◽  
Far Field ◽  
Q Factor ◽  
Field Radiation ◽  
The Continuum

Bound states in the continuum (BICs) correspond to a particular leaky mode with an infinitely large quality-factor (Q-factor) located within the continuum spectrum. To date, most of the research work reported focuses on the BIC-enhanced light matter interaction due to its extreme near-field confinement. Little attention has been paid to the scattering properties of the BIC mode. In this work, we numerically study the far-field radiation manipulation of BICs by exploring multipole interference. By simply breaking the symmetry of the silicon metasurface, an ideal BIC is converted to a quasi-BIC with a finite Q-factor, which is manifested by the Fano resonance in the transmission spectrum. We found that both the intensity and directionality of the far-field radiation pattern can not only be tuned by the asymmetric parameters but can also experience huge changes around the resonance. Even for the same structure, two quasi-BICs show a different radiation pattern evolution when the asymmetric structure parameter d increases. It can be found that far-field radiation from one BIC evolves from electric-quadrupole-dominant radiation to toroidal-dipole-dominant radiation, whereas the other one shows electric-dipole-like radiation due to the interference of the magnetic dipole and electric quadrupole with the increasing asymmetric parameters. The result may find applications in high-directionality nonlinear optical devices and semiconductor lasers by using a quasi-BIC-based metasurface.

scholarly journals Near-field analysis of bound states in the continuum in photonic crystal slabs

2020 ◽  
Vol 28 (11) ◽  
pp. 16288
Author(s):  
Shiwei Dai ◽  
Peng Hu ◽  
Dezhuan Han
Keyword(s):  
Photonic Crystal ◽  
Bound States ◽  
Near Field ◽  
Field Analysis ◽  
Photonic Crystal Slabs ◽  
The Continuum

scholarly journals Analogue of Electromagnetically Induced Transparency in an All-Dielectric Double-Layer Metasurface Based on Bound States in the Continuum

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2343
Author(s):  
Fengyan He ◽  
Jianjun Liu ◽  
Guiming Pan ◽  
Fangzhou Shu ◽  
Xufeng Jing ◽  
...  
Keyword(s):  
Double Layer ◽  
Bound States ◽  
Electromagnetically Induced Transparency ◽  
Near Field ◽  
Relative Displacement ◽  
Photonic Devices ◽  
Field Coupling ◽  
Potential Applications ◽  
Induced Transparency ◽  
The Continuum

Bound states in the continuum (BICs) have attracted much attention due to their infinite Q factor. However, the realization of the analogue of electromagnetically induced transparency (EIT) by near-field coupling with a dark BIC in metasurfaces remains challenging. Here, we propose and numerically demonstrate the realization of a high-quality factor EIT by the coupling of a bright electric dipole resonance and a dark toroidal dipole BIC in an all-dielectric double-layer metasurface. Thanks to the designed unique one-dimensional (D)–two-dimensional (2D) combination of the double-layer metasurface, the sensitivity of the EIT to the relative displacement between the two layer-structures is greatly reduced. Moreover, several designs for widely tunable EIT are proposed and discussed. We believe the proposed double-layer metasurface opens a new avenue for implementing BIC-based EIT with potential applications in filtering, sensing and other photonic devices.

scholarly journals Unveiling the Symmetry Protection of Bound States in the Continuum with Terahertz Near-Field Imaging

ACS Photonics ◽  
2021 ◽  
Author(s):  
Niels J.J. van Hoof ◽  
Diego R. Abujetas ◽  
Stan E.T. ter Huurne ◽  
Francesco Verdelli ◽  
Giel C.A. Timmermans ◽  
...  
Keyword(s):  
Bound States ◽  
Near Field ◽  
Near Field Imaging ◽  
Field Imaging ◽  
The Continuum

Bound states in the continuum in double-hole array perforated in a layer of photonic crystal slab

2019 ◽  
Vol 12 (12) ◽  
pp. 125002 ◽  
Author(s):  
Suxia Xie ◽  
Changzhong Xie ◽  
Song Xie ◽  
Jie Zhan ◽  
Zhijian Li ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Bound States ◽  
Hole Array ◽  
Photonic Crystal Slab ◽  
The Continuum

scholarly journals Differentiating and quantifying exosome secretion from a single cell using quasi-bound states in the continuum

Nanophotonics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1081-1086 ◽  
Author(s):  
Abdoulaye Ndao ◽  
Liyi Hsu ◽  
Wei Cai ◽  
Jeongho Ha ◽  
Junhee Park ◽  
...  
Keyword(s):  
Single Cell ◽  
Optical Sensors ◽  
Figure Of Merit ◽  
Bound States ◽  
Single Cell Analysis ◽  
Optical Cavity ◽  
High Sensitivity ◽  
Cell Secretion ◽  
The Continuum ◽  
Refractive Index Detection

AbstractOne of the key challenges in biology is to understand how individual cells process information and respond to perturbations. However, most of the existing single-cell analysis methods can only provide a glimpse of cell properties at specific time points and are unable to provide cell secretion and protein analysis at single-cell resolution. To address the limits of existing methods and to accelerate discoveries from single-cell studies, we propose and experimentally demonstrate a new sensor based on bound states in the continuum to quantify exosome secretion from a single cell. Our optical sensors demonstrate high-sensitivity refractive index detection. Because of the strong overlap between the medium supporting the mode and the analytes, such an optical cavity has a figure of merit of 677 and sensitivity of 440 nm/RIU. Such results facilitate technological progress for highly conducive optical sensors for different biomedical applications.

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