scholarly journals Transformation of guided modes into bound states in the continuum

2021 ◽  
Vol 2015 (1) ◽  
pp. 012078
Author(s):  
Aleksandra A. Kutuzova ◽  
Mikhail V. Rybin
Keyword(s):  
Field Distribution ◽  
Brillouin Zone ◽  
Bound States ◽  
Periodic Array ◽  
Leaky Modes ◽  
Guided Modes ◽  
Silicon Based ◽  
Symmetry Protected ◽  
Related Mode ◽  
The Continuum

Abstract We study a silicon-based structure composed of parallel rods arranged in a periodic array. The structure supports guided modes which due to the deformation of structure in general become leaky modes. At the same time the modes split at the Brillouin zone surface by a pair with certain symmetry. Here we report on guided modes transformation into symmetry-protected BIC under deforming the structure, because of inherent field distribution governed by the Bragg-related mode hybridization.

scholarly journals Polarization-selective modulation of supercavity resonances originating from bound states in the continuum

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Chan Kyaw ◽  
Riad Yahiaoui ◽  
Joshua A. Burrow ◽  
Viet Tran ◽  
Kyron Keelen ◽  
...  
Keyword(s):  
Strong Coupling ◽  
Bound States ◽  
Photonic Band Gap ◽  
Incidence Angle ◽  
Polarization State ◽  
Normal Incidence ◽  
Polarization Angle ◽  
Sensing Applications ◽  
Symmetry Protected ◽  
The Continuum

AbstractBound states in the continuum (BICs) are widely studied for their ability to confine light, produce sharp resonances for sensing applications and serve as avenues for lasing action with topological characteristics. Primarily, the formation of BICs in periodic photonic band gap structures are driven by symmetry incompatibility; structural manipulation or variation of incidence angle from incoming light. In this work, we report two modalities for driving the formation of BICs in terahertz metasurfaces. At normal incidence, we experimentally confirm polarization driven symmetry-protected BICs by the variation of the linear polarization state of light. In addition, we demonstrate through strong coupling of two radiative modes the formation of capacitively-driven Freidrich-Wintgen BICs, exotic modes which occur in off-Γ points not accessible by symmetry-protected BICs. The capacitance-mediated strong coupling at 0° polarization is verified to have a normalized coupling strength ratio of 4.17% obtained by the Jaynes-Cummings model. Furthermore, when the polarization angle is varied from 0° to 90° (0° ≤ ϕ < 90°), the Freidrich-Wintgen BIC is modulated until it is completely switched off at 90°.

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 Bound states in the continuum in periodic structures with structural disorder

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ekaterina E. Maslova ◽  
Mikhail V. Rybin ◽  
Andrey A. Bogdanov ◽  
Zarina F. Sadrieva
Keyword(s):  
Bound States ◽  
Periodic Structures ◽  
Structural Disorder ◽  
Practical Implementation ◽  
Photonic Structure ◽  
Mode Localization ◽  
Effective Reduction ◽  
System Length ◽  
Symmetry Protected ◽  
The Continuum

Abstract We study the effect of structural disorder on the transition from the bound states in the continuum (BICs) to quasi-BICs by the example of the periodic photonic structure composed of two layers of parallel dielectric rods. We uncover the specificity in the robustness of the symmetry-protected and accidental BICs against various types of structural disorder. We analyze how the spatial mode localization induced by the structural disorder results in an effective reduction of the system length and limits the Q factor of quasi-BICs. Our results are essential for the practical implementation of BICs especially in natural and self-assembled photonic structures, where the structural disorder plays a crucial role.

Symmetry-protected bound states in the continuum supported by all-dielectric metasurfaces

2019 ◽  
Vol 100 (6) ◽  
Author(s):  
Shiyu Li ◽  
Chaobiao Zhou ◽  
Tingting Liu ◽  
Shuyuan Xiao
Keyword(s):  
Bound States ◽  
Symmetry Protected ◽  
The Continuum

Polarization insensitive symmetry protected quasi-bound states in the continuum at terahertz band

2021 ◽  
Vol 130 (23) ◽  
pp. 233102
Author(s):  
Lei Wang ◽  
Zhenyu Zhao ◽  
Mingjie Du ◽  
Hua Qin ◽  
Rajour Tanyi Ako ◽  
...  
Keyword(s):  
Bound States ◽  
Terahertz Band ◽  
Polarization Insensitive ◽  
Symmetry Protected ◽  
The Continuum

All-optical tuning of symmetry protected quasi bound states in the continuum

2019 ◽  
Vol 115 (14) ◽  
pp. 141103 ◽  
Author(s):  
Nicholas Karl ◽  
Polina P. Vabishchevich ◽  
Sheng Liu ◽  
Michael B. Sinclair ◽  
Gordon A. Keeler ◽  
...  
Keyword(s):  
Bound States ◽  
All Optical ◽  
Symmetry Protected ◽  
The Continuum

scholarly journals Geometry symmetry-free and higher-order optical bound states in the continuum

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qingjia Zhou ◽  
Yangyang Fu ◽  
Lujun Huang ◽  
Qiannan Wu ◽  
Andrey Miroshnichenko ◽  
...  
Keyword(s):  
Significant Role ◽  
Bound States ◽  
Higher Order ◽  
Multiple Objects ◽  
Material Parameters ◽  
Geometrical Symmetry ◽  
Geometric Symmetry ◽  
Symmetry Protected ◽  
Zero Index ◽  
The Continuum

AbstractGeometrical symmetry plays a significant role in implementing robust, symmetry-protected, bound states in the continuum (BICs). However, this benefit is only theoretical in many cases since fabricated samples’ unavoidable imperfections may easily break the stringent geometrical requirements. Here we propose an approach by introducing the concept of geometrical-symmetry-free but symmetry-protected BICs, realized using the static-like environment induced by a zero-index metamaterial (ZIM). We find that robust BICs exist and are protected from the disordered distribution of multiple objects inside the ZIM host by its physical symmetries rather than geometrical ones. The geometric-symmetry-free BICs are robust, regardless of the objects’ external shapes and material parameters in the ZIM host. We further show theoretically and numerically that the existence of those higher-order BICs depends only on the number of objects. By practically designing a structural ZIM waveguide, the existence of BICs is numerically confirmed, as well as their independence on the presence of geometrical symmetry. Our findings provide a way of realizing higher-order BICs and link their properties to the disorder of photonic systems.

Sign in / Sign up

Export Citation Format

Share Document