Dielectric metasurfaces supporting symmetry-protected bound states in the continuum (SP-BICs) have emerged as an attractive platform for manipulating light–matter interactions on the nanoscale. However, quasi-BIC with a high quality factor (Q-factor) by releasing SP-BIC is still a challenge in practice due to the Q-factor sensitivity to asymmetric parameters and the limited level of fabrication. Here, we present a universal perspective aiming at achieving high-Q-factor quasi-BICs through the efficient perturbation of eigenfields. This approach affords the flexibility to select scaling laws of the Q-factor, and a larger Q-factor can be obtained under the disturbance of the weak field region for the same asymmetric parameters. Such findings have been extended to classical nanostructures, such as dimeric nanobars, splitting rings, and nanodisks. Finally, square nanodisks embedded with air holes at different positions are used as an example to experimentally confirm our findings. Our method provides a new idea for the release of high-Q-factor quasi-BICs and paves the way for the realization of high-performance optical devices based on a high Q-factor. 

Selective Perturbation of Eigenfield Enables High-Q Quasi-Bound States in the Continuum in Dielectric Metasurfaces

Flexible control of intrinsic chiroptical responses within compact nanostructures is crucial for flat optics, topological photonics, and chiroptics. However, previous approaches require complicated patterns with both in-plane and out-of-plane mirror symmetry breaking to achieve intrinsic chirality, and their chiroptical responses cannot be dynamically controlled as well. Herein, we demonstrated that near-perfect intrinsic circular dichroism (CD) can be achieved within a lithography-free structure consisting of the twisted bilayer α-MoO3 separated by a vanadium dioxide (VO2) film. By twisting the bilayer α-MoO3, dual-band intrinsic chiroptical responses can be realized due to the excitations of the hyperbolic phonon polaritons modes in the mid-infrared. It is the spin-selected average electric-field enhancement instead of the chiral absorption that is responsible for the intrinsic CD of the device. In addition, the chiroptical responses are insensitive to the variation of the thickness of the structure as well as the incident angle, and high contrast CD can be dynamically tuned by varying the volume fraction of VO2.

Tailoring intrinsic chiroptical responses via twisted bilayer α-MoO3 separated by a VO2 film

Emerging applications of metasurfaces in classical and quantum optics are driving the need for precise polarization control of nearly-degenerate, high quality (Q)-factor modes. However, current approaches to creating specifically polarized pairs of modes force a trade-off between maintaining high Q factors and robustness. Here, we solve this challenge by employing pairwise generation, annihilation, and positioning of polarization singularities, derived from symmetry-guaranteed pairs of symmetry-protected bound states in the continuum. We experimentally demonstrate this design paradigm in silicon metasurfaces with mode splittings of ≈20  nm, mode splitting deviations as low as 1 nm, and Q factors up to 200. This approach opens new avenues for enhancing metasurface performance across a diverse range of applications, including sensing, modulating, nonlinear mixing, and generating quantum light.

Dual-Band Polarization Control with Pairwise Positioning of Polarization Singularities in Metasurfaces

Selective IR wavelengths multichannel filter based on the one-dimensional topological photonic crystals comprising hyperbolic metamaterial

Photonic spin Hall effect (PSHE) can be achieved by using the patterned structures or metal/dielectric multilayers in the nanophotonic systems; however, the complicated structures of these devices hinder their further applications. Herein, we demonstrate that highly directional PSHE can be realized through the excitation of hyperbolic phonon polaritons (HPPs) in a comparably simple architecture based on an anisotropic α-MoO3 thin film. It is shown that the propagation of the HPP modes of α-MoO3 in the reststrahlen (RS) bands exhibits topological transitions between open hyperbola and closed ellipse in both real space and momentum space (k-space) due to the extreme in-plane anisotropy. Specifically, larger dispersion angle possesses larger figure of merit (FoM), and high k mode of HPPs exhibits robust propagation properties at the maximum dispersion angle. Spin-selected propagation with asymmetric ratio of intensity equal to ±0.94 can be realized by changing the handedness of the dipole emitters. By changing the incident wavelengths of the RS bands, the propagation angle of the HPP modes can be dynamically tuned in wide angular and wavelength ranges.

Hyperbolic phonon polaritons-induced photonic spin Hall effect in an 
 α
 -MoO3 thin film

Dual-band polarization-independent high quality factor Fano resonances using a twisted tetrameric nanohole slab

Optical anisotropy of α-MoO3 in its reststrahlen (RS) bands provides exciting opportunities for constructing the polarization-dependent devices. However, achieving broadband anisotropic absorptions through the same α-MoO3 arrays is still challenging. In this study, we demonstrate that selective broadband absorption can be achieved by using the same α-MoO3 square pyramid arrays (SPAs). For both the x and y polarizations, the absorption responses of the α-MoO3 SPAs calculated by using the effective medium theory (EMT) agreed well with those of the FDTD, indicating the excellent selective broadband absorption of the α-MoO3 SPAs are associated with the resonant hyperbolic phonon polaritons (HPhPs) modes assisted by the anisotropic gradient antireflection (AR) effect of the structure. The near-field distribution of the absorption wavelengths of the α-MoO3 SPAs shows that the magnetic-field enhancement of the lager absorption wavelength tends to shift to the bottom of the α-MoO3 SPAs due to the lateral Fabry-Pérot (F-P) resonance, and the electric-field distribution exhibits the ray-like light propagation trails due to the resonance nature of the HPhPs modes. In addition, broadband absorption of the α-MoO3 SPAs can be maintained if the width of the bottom edge of the α-MoO3 pyramid is large than 0.8 μm, and excellent anisotropic absorption performances are almost immune to the variations of the thickness of the spacer and the height of the α-MoO3 pyramid. 

/pdf/selective-excitation-of-hyperbolic-phonon-polaritons-induced-2nvuz5pr.pdf

Selective excitation of hyperbolic phonon polaritons-induced broadband absorption via α-MoO3 square pyramid arrays

Active control of induced reflection is crucial for many potential applications ranging from slowing light to biosensing devices. However, most previous approaches require patterned nanostructures to achieve controllable induced reflection, which hinders their further applications due to complicated architectures. Herein, we propose a lithography-free multilayered structure to achieve the induced reflection through the coupling of dual-topological-interface-states. The multilayers consist of two one-dimensional (1D) photonic crystals (PCs) and an Ag film separated by a Spacer, topological edge state (TES) and topological Tamm state (TTS) can be excited simultaneously and their coupling induces the reflection window. The coupled-oscillator model is proposed to mimic the coupling between the TES and TTS, and the analytical results are in good agreement with finite element method (FEM). In addition, the TES-TTS induced reflection is robust to the variation of structural parameters. By integrating an ultra-thin phase-change film of Ge2Sb2Te5 (GST) into the multilayers, the induced reflection can be switched through the phase transition of the GST film. The multipole decomposition reveals that the vanished reflection window is arising from the disappearance of TTS associated with the toroidal dipole (TD) mode.

Configurable dual-topological-interface-states induced reflection in hybrid multilayers consisting of a Ge₂Sb₂Te₅ film

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of {limit} columns in the table. Remove at least 1 column to add or create another one.

Chui Pian

Author Tools

Chat about Author

Papers

Dual-band polarization-independent high quality factor Fano resonances using a twisted tetrameric nanohole slab

Tailoring intrinsic chiroptical responses via twisted bilayer α-MoO3 separated by a VO2 film

Selective excitation of hyperbolic phonon polaritons-induced broadband absorption via α-MoO3 square pyramid arrays

Configurable dual-topological-interface-states induced reflection in hybrid multilayers consisting of a Ge₂Sb₂Te₅ film

Hyperbolic phonon polaritons-induced photonic spin Hall effect in an α -MoO3 thin film