Circular Dichroism Enhancement and Biosensing Application of Composite Dielectric Chiral Nanostructures

Phys. Chem. Chem. Phys.

et al. 2022

Self Cite

Section: Resultscontrasting

confidence: 70%

“…This was due to SPP Xy and SPP Yx mainly being located in the Si 3 N 4 layer. Compared with previous research results ( S = 60/RIU 48 ), the maximal S in this paper was improved by about 5 times.…”

Section: Resultscontrasting

confidence: 65%

Induced circular dichroism of achiral dielectric elliptical hole arrays with a monolayer borophene film

Phys. Chem. Chem. Phys.

et al. 2022

Self Cite

“…The electrical conductivity of VO 2 can be adjusted between 10 and 10 5 S/m. These indicate the dielectric state and the metallic state, respectively . The refractive index of VO 2 is taken as 3.…”

Section: Structure Theory and Designmentioning

confidence: 99%

“…Due to the weak coupling between lights and chiral molecules, chiral molecules show weak CD effects. However, the artificial chiral nanostructures can be strongly coupled with light, which leads to their CD signals being stronger than the CD signals of chiral molecules by several orders of magnitude. ,, Therefore, artificial chiral nanostructures provide a new platform for chiral catalysis, chiral molecular sensings, ,, and circularly polarized device design …”

Section: Introductionmentioning

confidence: 99%

“…Since molybdenum disulfide (MoS 2 ) has a direct band gap in the near-infrared and visible light ranges, researchers have proposed various methods to enhance the absorption of the resonator by placing MoS 2 in different resonators. , For example, a resonant nanostructure with a monolayer MoS 2 shows a UNB perfect absorption in visible light . To achieve dynamically tunable signals, many tunable materials such as graphene, , vanadium dioxide, , and GST , have been introduced into nanostructures. Therefore, the introduction of MoS 2 and VO 2 into the chiral nanostructure based on the Bragg reflector is expected to obtain strong and dynamically adjustable UNB CD signals.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Enhancement and Sensing Application of Ultra-Narrowband Circular Dichroism in the Chiral Nanostructures Based on Monolayer MoS₂ and a Distributed Bragg Reflector

ACS Appl. Mater. Interfaces

et al. 2022

Self Cite

Narrowband circular dichroism (CD) has aroused wide concerns in high-sensitivity detections of chiral molecular and chiral catalysis. Nevertheless, the dynamical adjustment of ultranarrowband (UNB) CD signals is hard to achieve. In this work, single-layer molybdenum disulfide (MoS 2 ), vanadium dioxide (VO 2 ), and a distributed Bragg reflector (DBR) are introduced into X-shaped chiral nanostructures (XCNs) for overcoming the above challenge. The simulation results show that XCNs can generate four strong UNB CD signals in the near-infrared band, and XCNs/MoS 2 can further enhance the UNB CD signals. The full width at half-minimum of UNB CD signals can reach 0.14 nm. The electric field distributions of XCNs/MoS 2 show that the four CD signals originate from the coupling between the guided mode resonances along the x and y axes in the VO 2 layer and the Tamm plasmon polaritons along the x and y axes in the DBR layer. Four UNB CD peaks can be actively tuned by varying the structural parameters, the number of MoS 2 layers, and the environmental temperature. The FOM of XCNs/MoS 2 can reach 1487 by changing the refractive index of the DRB layers. These findings contribute to the design of UNB chiral devices and provide new possibilities for environmental monitoring and ultrasensitive detection of chiral molecules.

Ultrathin Twisted Stacked Gap‐Plasmon Metasurface with Giant and Tunable Shortwave Infrared Chirality

Han

Advanced Optical Materials

Sun

et al. 2023

Ultrathin optical components with giant circular dichroism hold great promise for polarization‐sensitive nanophotonics. However, existing chiral metamaterials often rely on complex‐shaped nanoinclusions, and there remains a paucity of designs active in the shortwave infrared (SWIR) useful for telecommunication and night vision. Here a detailed numerical analysis of the chiroptical response of a simple twisted stacked variant of gap‐plasmon metasurface is presented based on periodic nanohole arrays. Impressively, the 100‐nm free‐standing plasmonic metasurface can attain a thickness‐normalized ellipticity of up to 74.2° µm−1 with tunable bands in the SWIR. Strong and robust optical activity is achieved through energy confinement by gap surface plasmons and effective inter‐nanohole coupling, resulting in an intense superchiral near field. The ultrathin plasmonic metasurface serves as an excellent platform for refractive index sensing with a sensitivity Sn of up to 648.1 nm RIU−1 and field‐enhanced enantiodiscrimination. The simple metasurface with strong SWIR chirality can enjoy a multitude of potential applications including polarization‐sensitive photodetection, optical telecommunication, machine vision, medical imaging, and spectroscopy. These findings also offer insights into some fundamental design principles for twisted stacked aperture‐based metasurfaces and should facilitate the development of new chiral metamaterials with exceptional performance.