Metallic nanostructures supporting surface plasmons are crucial for various ultrathin photonic devices.However,these applications are often limited by inherent metallic losses.Significant efforts have been made to ach...Metallic nanostructures supporting surface plasmons are crucial for various ultrathin photonic devices.However,these applications are often limited by inherent metallic losses.Significant efforts have been made to achieve high quality-factor(Q-factor)resonances in plasmonic metasurfaces,particularly through surface lattice resonances(SLRs)and bound states in the continuum(BICs).Despite these advances,a direct comparison between these two mechanisms remains unexplored.Here,we report a reusable plasmonic metasurface that supports multiple high-Q resonances by leveraging hybrid plasmonic–photonic modes.By systematically tuning the lattice constant and dielectric cladding thickness,we achieve substantial Q-factor enhancements of both SLRs and BICs in a monolithic device with a small footprint of 200μm×200μm by using an incoherent light source.A direct comparison between these two resonances is also discussed.This high-Q performance holds significant promise for applications in sensing,lasing,and nonlinear and quantum optics,paving the way for the development of next-generation nanophotonic devices.展开更多
Light beams with a helical phase-front possess orbital angular momentum along their direction of propagation in addition to the spin angular momentum that describes their polarisation.Until recently,it was thought tha...Light beams with a helical phase-front possess orbital angular momentum along their direction of propagation in addition to the spin angular momentum that describes their polarisation.Until recently,it was thought that these two‘rotational’motions of light were largely independent and could not be coupled during light–matter interactions.However,it is now known that interactions with carefully designed complex media can result in spin-to-orbit coupling,where a change of the spin angular momentum will modify the orbital angular momentum and vice versa.In this work,we propose and demonstrate that the birefringence of plasmonic nanostructures can be wielded to transform circularly polarised light into light carrying orbital angular momentum.A device operating at visible wavelengths is designed from a space-variant array of subwavelength plasmonic nano-antennas.Experiment confirms that circularly polarised light transmitted through the device is imbued with orbital angular momentum of 62"(with conversion efficiency of at least 1%).This technology paves the way towards ultrathin orbital angular momentum generators that could be integrated into applications for spectroscopy,nanoscale sensing and classical or quantum communications using integrated photonic devices.展开更多
Subwavelength metal-dielectric plasmonic metasurfaces enable light management beyond the diffraction limit.However,a costeffective and reliable fabrication method for such structures remains a major challenge hinderin...Subwavelength metal-dielectric plasmonic metasurfaces enable light management beyond the diffraction limit.However,a costeffective and reliable fabrication method for such structures remains a major challenge hindering their full exploitation.Here,we propose a simple yet powerful manufacturing route for plasmonic metasurfaces based on a bottom-up approach.The fabricated metasurfaces consist of a dense distribution of randomly oriented nanoscale scatterers composed of aluminum(Al)nanohole-disk pairs,which exhibit angle-independent scattering that is tunable across the entire visible spectrum.The macroscopic response of the metasurfaces is controlled via the properties of an isolated Al nanohole-disk pair at the nanoscale.In addition,the optical field confinement at the scatterers and their random distribution of sizes result in a strongly enhanced Raman signal that enables broadly tunable excitation using a single substrate.This unique combination of a reliable and lithography-free methodology with the use of aluminum permits the exploitation of the full potential of random plasmonic metasurfaces for diagnostics and coloration.展开更多
Optical metasurfaces,comprising subwavelength quasi-planar nanostructures,constitute a universal platform for manipulating the amplitude,phase,and polarization of light,thus paving a way for the next generation of hig...Optical metasurfaces,comprising subwavelength quasi-planar nanostructures,constitute a universal platform for manipulating the amplitude,phase,and polarization of light,thus paving a way for the next generation of highly integrated multifunctional optical devices.In this work,we introduce a reflective metasurface for the generation of a complete(angularly resolved)polarization set by randomly interleaving anisotropic plasmonic meta-atoms acting as nanoscale wave plates.In the proof-of-concept demonstration,we achieve multidirectional beam-steering into different polarization channels forming a complete set of polarization states,which can also be dynamically altered by switching the spin of incident light.The developed design concept represents a significant advancement in achieving flat polarization optics with advanced functionalities.展开更多
Vortex beams carrying orbital angular momentum(OAM)are of great significance for high-capacity communication and super-resolution imaging.However,there is a huge gap between the free-space vortices(FVs)and plasmonic v...Vortex beams carrying orbital angular momentum(OAM)are of great significance for high-capacity communication and super-resolution imaging.However,there is a huge gap between the free-space vortices(FVs)and plasmonic vortices(PVs)on chips,and active manipulation as well as multiplexing in more channels have become a pressing demand.In this work,we demonstrate a terahertz(THz)cascaded metadevice composed of a helical plasmonic metasurface,a liquid crystal(LC)layer,and a helical dielectric metasurface.By spin-orbital angular momentum coupling and photon state superposition,PVs and FVs are generated with mode purity of over 85%on average.Due to the inversion asymmetric design of the helical metasurfaces,the parity symmetry breaking of OAM is realized(the topological charge numbers no longer occur in positive and negative pairs,but all are positive),generating 6 independent channels associated with the decoupled spin states and the near-/far-field positions.Moreover,by the LC integration,dynamic mode switching and energy distribution can be realized,finally obtaining up to 12 modes with a modulation ratio of above 70%.This active tuning and multi-channel multiplexing metadevice establishes a bridge connection between the PVs and FVs,exhibiting promising applications in THz communication,intelligent perception,and information processing.展开更多
Plasmonic metasurfaces supporting high-quality(Q)resonances offer unprecedented ways for controlling light-matterinteraction at the nanoscale,yet scalable fabrication of such sophisticated nanostructures still relies ...Plasmonic metasurfaces supporting high-quality(Q)resonances offer unprecedented ways for controlling light-matterinteraction at the nanoscale,yet scalable fabrication of such sophisticated nanostructures still relies on expensive andmulti-step fabrication routes,hindering their practical application.Here,we produced plasmonic metasurfacescomposed of the regular arrangement of hollow protruding nanobumps via direct femtosecond laser patterning ofthin gold films.By using comprehensive optical modeling,infrared spectroscopy and angle-resolved third harmonicgeneration experiments,we justified that such laser-printed nanostructures support symmetry-protected plasmonicquasi-bound states in the continuum(qBIC)with a measured Q-factor up to 20.Moreover,under critical couplingconditions that match the radiative and nonradiative losses of the high-Q mode,the metasurfaces demonstrate thethird harmonic generation enhanced by a factor of≈10^(5)as compared to the smooth Au film benchmark,provingstructure efficiency for nonlinear conversion.Finally,by taking advantage of the simplicity and straightforwardcharacter of the laser printing process,we realized a field-effect transistor device with HgTe quantum dots as an activemedium and qBIC-supporting plasmonic metasurface imprinted over drain and source electrodes.The resultingmetasurface-empowered device operates at 200 K and 5 V bias voltage and demonstrates superior specific detectivityaround 8.7×10^(11)at the plasmonic-qBIC spectral region and fast response time,holding promise for the realization ofadvanced shortwave infrared photodetectors.展开更多
A polarization-insensitive unidirectional spoof surface plasmon polariton（SPP） coupler mediated by a gradient metasurface is proposed. The field distributions and average Poynting vector of the coupled spoof SPPs ar...A polarization-insensitive unidirectional spoof surface plasmon polariton（SPP） coupler mediated by a gradient metasurface is proposed. The field distributions and average Poynting vector of the coupled spoof SPPs are analyzed. The simulated and experimental results support the theoretical analysis and indicate that the designed gradient metasurface can couple both the parallel-polarized and normally-polarized incident waves to the spoof SPPs propagating in the same direction at about 5 GHz.展开更多
We propose a low-cost plasmonic metasurface integrated with single-layer graphene for dynamic modulation of midinfrared light. The plasmonic metasurface is composed of an array of split magnetic resonators（MRs） wher...We propose a low-cost plasmonic metasurface integrated with single-layer graphene for dynamic modulation of midinfrared light. The plasmonic metasurface is composed of an array of split magnetic resonators（MRs） where a nano slit is included. Extraordinary optical transmission（EOT） through the deep subwavelength slit is observed by excitation of magnetic plasmons in the split MRs. Furthermore, the introduction of the slit provides strongly enhanced fields around the graphene layer, leading to a large tuning effect on the EOT by changing the Fermi energy of the graphene. The proposed metasurface can be utilized as an optical modulator with a broad modulation width（15 μm） or an optical switch with a high on/off ratio（〉 100）. Meanwhile, the overall thickness of the metasurface is 430 nm, which is tens of times smaller than the operating wavelength. This work may have potential applications in mid-infrared optoelectrical devices and give insights into reconfigurable flat optics and optoelectronics.展开更多
A polarization control device was developed using a plasmonic metasurface with the aim of achieving the desired polarization state. In this study, the Ag metal grating structure was fabricated as a plasmonic metasurfa...A polarization control device was developed using a plasmonic metasurface with the aim of achieving the desired polarization state. In this study, the Ag metal grating structure was fabricated as a plasmonic metasurface by electron beam lithography and a lift-off process. The phase difference of the fabricated sample was 21.0°. This value is almost consistent with the simulation (24.0°). Then, the transmission and phase difference is dependent on the structural parameter. Because of the propagation of surface plasmon polariton at the interface between Ag and SiO<sub>2</sub> or Ag and air, it is believed that the transmittance and the phase difference for TM polarized light can be controlled by the structural parameters. By plotting on the Poincaré sphere after calculating the S-parameter by simulation, it is clear that the arbitrary polarization status can be controlled by the structural parameter.展开更多
The localized surface plasmon resonance metasurface is a research hotspot in the sensing field since it can enhance the light-matter interaction in the nanoscale,but the wavelength sensitivity is far from comparable w...The localized surface plasmon resonance metasurface is a research hotspot in the sensing field since it can enhance the light-matter interaction in the nanoscale,but the wavelength sensitivity is far from comparable with that of prism-coupled surface plasmon polariton(SPP).Herein,we propose and demonstrate an ultrasensitive angular interrogation sensor based on the transverse electric mode surface lattice resonance(SLR)mechanism in an all-metal metasurface.In theory,we derive the sensitivity function in detail and emphasize the refraction effect at the air-solution interface,which influences the SLR position and improves the sensitivity performance greatly in the wide-angle.In the measurement,a broadband light source substitutes the single-wavelength laser generally used in traditional angular sensing,and the measured SLR wavelength of broadband illuminant at normal incidence is defined as the single wavelength,avoiding the sensitivity loss from the large angle.The experimental sensitivity can reach 4304.35°/RIU,promoting an order of magnitude compared to those of SPP-sensors.This research provides a novel theory as well as the corresponding crucial approach to achieving ultrasensitive angular sensing.展开更多
Achieving the precise control over high-quality(Q)resonances,particularly bound states in the continuum(BICs),within plasmonic metasurfaces remains a substantial challenge due to inherent material losses,which can und...Achieving the precise control over high-quality(Q)resonances,particularly bound states in the continuum(BICs),within plasmonic metasurfaces remains a substantial challenge due to inherent material losses,which can undermine the modulation efficiency and device performance in practical settings.Here,we introduce a mechanism,termed dual-channel-driven BICs,which exploits the cross-coupling between surface plasmon polaritons and guided mode resonances to enable the delicate formation and manipulation of high-Q bound states in dissipative plasmonic platforms.展开更多
This review examines imaging-based nanophotonic biosensing and interferometric label-free imaging,with a particular focus on vesicle detection.It specifically compares dielectric and plasmonic metasurfaces for label-f...This review examines imaging-based nanophotonic biosensing and interferometric label-free imaging,with a particular focus on vesicle detection.It specifically compares dielectric and plasmonic metasurfaces for label-free protein and extracellular vesicle detection,highlighting their respective advantages and limitations.Key topics include:(ⅰ)refractometric sensing principles using resonant dielectric and plasmonic surfaces;(ⅱ)state-of-the-art developments in both plasmonic and dielectric nanostructured resonant surfaces;(ⅲ)a detailed comparison of resonance characteristics,including amplitude,quality factor,and evanescent field enhancement;and(ⅳ)the relationship between sensitivity,near-field enhancement,and analyte overlap in different sensing platforms.The review provides insights into the fundamental differences between plasmonic and dielectric platforms,discussing their fabrication,integration potential,and suitability for various analyte sizes.It aims to offer a unified,application-oriented perspective on the potential of these resonant surfaces for biosensing and imaging,aiming at addressing topics of interest for both photonics experts and potential users of these technologies.展开更多
We review the physics and some applications of photonic structures designed for the realization of strong nonlinear chiroptical response.We pay much attention to the recent strategy of utilizing different types of opt...We review the physics and some applications of photonic structures designed for the realization of strong nonlinear chiroptical response.We pay much attention to the recent strategy of utilizing different types of optical resonances in metallic and dielectric subwavelength structures and metasurfaces,including surface plasmon resonances,Mie resonances,lattice-guided modes,and bound states in the continuum.We summarize earlier results and discuss more recent developments for achieving large circular dichroism combined with the high efficiency of nonlinear harmonic generation.展开更多
A harmonic vortex beam is a typical vector beam with a helical wavefront at harmonic frequencies(e.g.,second and third harmonics). It provides an additional degree of freedom beyond spin-and orbitalangular momentum, w...A harmonic vortex beam is a typical vector beam with a helical wavefront at harmonic frequencies(e.g.,second and third harmonics). It provides an additional degree of freedom beyond spin-and orbitalangular momentum, which may greatly increase the capacity for communicating and encoding information. However, conventional harmonic vortex beam generators suffer from complex designs and a low nonlinear conversion efficiency. Here, we propose and experimentally demonstrate the generation of a large second-harmonic(SH) vortex beam with quasi-nonlinear spin–orbit interaction(SOI). Highquality SH vortex beams with large topological charges up to 28 are realized experimentally. This indicated that the quasi-angular-momentum of a plasmonic spiral phase plate at the excitation wavelength(topological charge, q) could be imprinted on the harmonic signals from the attached WS2 monolayer. The generated harmonic vortex beam has a topological charge of l_(n)= 2 nq(n is the harmonic order). The results may open new avenues for generating harmonic optical vortices for optical communications and enables novel multi-functional hybrid metasurface devices to manipulate harmonic beams.展开更多
基金National Natural Science Foundation of China(12174031,91950108,12161141010)National Key R&D Program of China(2022YFA1404301)。
文摘Metallic nanostructures supporting surface plasmons are crucial for various ultrathin photonic devices.However,these applications are often limited by inherent metallic losses.Significant efforts have been made to achieve high quality-factor(Q-factor)resonances in plasmonic metasurfaces,particularly through surface lattice resonances(SLRs)and bound states in the continuum(BICs).Despite these advances,a direct comparison between these two mechanisms remains unexplored.Here,we report a reusable plasmonic metasurface that supports multiple high-Q resonances by leveraging hybrid plasmonic–photonic modes.By systematically tuning the lattice constant and dielectric cladding thickness,we achieve substantial Q-factor enhancements of both SLRs and BICs in a monolithic device with a small footprint of 200μm×200μm by using an incoherent light source.A direct comparison between these two resonances is also discussed.This high-Q performance holds significant promise for applications in sensing,lasing,and nonlinear and quantum optics,paving the way for the development of next-generation nanophotonic devices.
文摘Light beams with a helical phase-front possess orbital angular momentum along their direction of propagation in addition to the spin angular momentum that describes their polarisation.Until recently,it was thought that these two‘rotational’motions of light were largely independent and could not be coupled during light–matter interactions.However,it is now known that interactions with carefully designed complex media can result in spin-to-orbit coupling,where a change of the spin angular momentum will modify the orbital angular momentum and vice versa.In this work,we propose and demonstrate that the birefringence of plasmonic nanostructures can be wielded to transform circularly polarised light into light carrying orbital angular momentum.A device operating at visible wavelengths is designed from a space-variant array of subwavelength plasmonic nano-antennas.Experiment confirms that circularly polarised light transmitted through the device is imbued with orbital angular momentum of 62"(with conversion efficiency of at least 1%).This technology paves the way towards ultrathin orbital angular momentum generators that could be integrated into applications for spectroscopy,nanoscale sensing and classical or quantum communications using integrated photonic devices.
基金supported by the Karlsruhe School of Optics and Photonics(KSOP,www.ksop.idschools.kit.edu)the Karlsruhe Nano Micro Facility(KNMF,www.kit.edu/knmf)+3 种基金a Helmholtz Research Infrastructure at Karlsruhe Institute of Technology(KIT,www.kit.edu)a BBSRC David Phillips fellowship(BB/K014617/1)ERC-2014-STG H2020639088support from the EPSRC(EP/G060649/1).
文摘Subwavelength metal-dielectric plasmonic metasurfaces enable light management beyond the diffraction limit.However,a costeffective and reliable fabrication method for such structures remains a major challenge hindering their full exploitation.Here,we propose a simple yet powerful manufacturing route for plasmonic metasurfaces based on a bottom-up approach.The fabricated metasurfaces consist of a dense distribution of randomly oriented nanoscale scatterers composed of aluminum(Al)nanohole-disk pairs,which exhibit angle-independent scattering that is tunable across the entire visible spectrum.The macroscopic response of the metasurfaces is controlled via the properties of an isolated Al nanohole-disk pair at the nanoscale.In addition,the optical field confinement at the scatterers and their random distribution of sizes result in a strongly enhanced Raman signal that enables broadly tunable excitation using a single substrate.This unique combination of a reliable and lithography-free methodology with the use of aluminum permits the exploitation of the full potential of random plasmonic metasurfaces for diagnostics and coloration.
基金funded by the Danmarks Frie Forskningsfond(1134-00010B)Villum Fonden(Award in Technical and Natural Sciences 2019 and Grant No.37372)Y.Deng would like to acknowledge the support from the China Scholarship Council(Grant No.202108330079).
文摘Optical metasurfaces,comprising subwavelength quasi-planar nanostructures,constitute a universal platform for manipulating the amplitude,phase,and polarization of light,thus paving a way for the next generation of highly integrated multifunctional optical devices.In this work,we introduce a reflective metasurface for the generation of a complete(angularly resolved)polarization set by randomly interleaving anisotropic plasmonic meta-atoms acting as nanoscale wave plates.In the proof-of-concept demonstration,we achieve multidirectional beam-steering into different polarization channels forming a complete set of polarization states,which can also be dynamically altered by switching the spin of incident light.The developed design concept represents a significant advancement in achieving flat polarization optics with advanced functionalities.
基金supported by the National Natural Science Foundation of China(62335012,62371258,624B2075,62205160,62435010)Young Scientific and Technological Talents in Tianjin(QN20230227)Fundamental Research Funds for the Central Universities,Nankai University(63231159).
文摘Vortex beams carrying orbital angular momentum(OAM)are of great significance for high-capacity communication and super-resolution imaging.However,there is a huge gap between the free-space vortices(FVs)and plasmonic vortices(PVs)on chips,and active manipulation as well as multiplexing in more channels have become a pressing demand.In this work,we demonstrate a terahertz(THz)cascaded metadevice composed of a helical plasmonic metasurface,a liquid crystal(LC)layer,and a helical dielectric metasurface.By spin-orbital angular momentum coupling and photon state superposition,PVs and FVs are generated with mode purity of over 85%on average.Due to the inversion asymmetric design of the helical metasurfaces,the parity symmetry breaking of OAM is realized(the topological charge numbers no longer occur in positive and negative pairs,but all are positive),generating 6 independent channels associated with the decoupled spin states and the near-/far-field positions.Moreover,by the LC integration,dynamic mode switching and energy distribution can be realized,finally obtaining up to 12 modes with a modulation ratio of above 70%.This active tuning and multi-channel multiplexing metadevice establishes a bridge connection between the PVs and FVs,exhibiting promising applications in THz communication,intelligent perception,and information processing.
基金supported by the Russian Science Foundation grant(No.24-19-00541)supported by the Russian Science Foundation grant(No.25-22-20034)+2 种基金support by the Federal Academic Leadership Program Priority 2030supported by the Research Grants Council of Hong Kong SAR(SRFS2324-1S04)Innovation and Technology Fund of Hong Kong SAR(ITS/027/22MX).
文摘Plasmonic metasurfaces supporting high-quality(Q)resonances offer unprecedented ways for controlling light-matterinteraction at the nanoscale,yet scalable fabrication of such sophisticated nanostructures still relies on expensive andmulti-step fabrication routes,hindering their practical application.Here,we produced plasmonic metasurfacescomposed of the regular arrangement of hollow protruding nanobumps via direct femtosecond laser patterning ofthin gold films.By using comprehensive optical modeling,infrared spectroscopy and angle-resolved third harmonicgeneration experiments,we justified that such laser-printed nanostructures support symmetry-protected plasmonicquasi-bound states in the continuum(qBIC)with a measured Q-factor up to 20.Moreover,under critical couplingconditions that match the radiative and nonradiative losses of the high-Q mode,the metasurfaces demonstrate thethird harmonic generation enhanced by a factor of≈10^(5)as compared to the smooth Au film benchmark,provingstructure efficiency for nonlinear conversion.Finally,by taking advantage of the simplicity and straightforwardcharacter of the laser printing process,we realized a field-effect transistor device with HgTe quantum dots as an activemedium and qBIC-supporting plasmonic metasurface imprinted over drain and source electrodes.The resultingmetasurface-empowered device operates at 200 K and 5 V bias voltage and demonstrates superior specific detectivityaround 8.7×10^(11)at the plasmonic-qBIC spectral region and fast response time,holding promise for the realization ofadvanced shortwave infrared photodetectors.
基金Project supported by the China Postdoctoral Science Foundation(Grant No.2015M580849)the National Natural Science Foundation of China(Grant Nos.61471292,61501365,61471388,6133100541404095,and 41390454)
文摘A polarization-insensitive unidirectional spoof surface plasmon polariton（SPP） coupler mediated by a gradient metasurface is proposed. The field distributions and average Poynting vector of the coupled spoof SPPs are analyzed. The simulated and experimental results support the theoretical analysis and indicate that the designed gradient metasurface can couple both the parallel-polarized and normally-polarized incident waves to the spoof SPPs propagating in the same direction at about 5 GHz.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11174062 and 51472057)
文摘We propose a low-cost plasmonic metasurface integrated with single-layer graphene for dynamic modulation of midinfrared light. The plasmonic metasurface is composed of an array of split magnetic resonators（MRs） where a nano slit is included. Extraordinary optical transmission（EOT） through the deep subwavelength slit is observed by excitation of magnetic plasmons in the split MRs. Furthermore, the introduction of the slit provides strongly enhanced fields around the graphene layer, leading to a large tuning effect on the EOT by changing the Fermi energy of the graphene. The proposed metasurface can be utilized as an optical modulator with a broad modulation width（15 μm） or an optical switch with a high on/off ratio（〉 100）. Meanwhile, the overall thickness of the metasurface is 430 nm, which is tens of times smaller than the operating wavelength. This work may have potential applications in mid-infrared optoelectrical devices and give insights into reconfigurable flat optics and optoelectronics.
文摘A polarization control device was developed using a plasmonic metasurface with the aim of achieving the desired polarization state. In this study, the Ag metal grating structure was fabricated as a plasmonic metasurface by electron beam lithography and a lift-off process. The phase difference of the fabricated sample was 21.0°. This value is almost consistent with the simulation (24.0°). Then, the transmission and phase difference is dependent on the structural parameter. Because of the propagation of surface plasmon polariton at the interface between Ag and SiO<sub>2</sub> or Ag and air, it is believed that the transmittance and the phase difference for TM polarized light can be controlled by the structural parameters. By plotting on the Poincaré sphere after calculating the S-parameter by simulation, it is clear that the arbitrary polarization status can be controlled by the structural parameter.
基金supported by the National Key R&D Program of China(Grant No.2021YFB3200100)the National Natural Science Foundation of China(Grant No.61931018 and 61974004)。
文摘The localized surface plasmon resonance metasurface is a research hotspot in the sensing field since it can enhance the light-matter interaction in the nanoscale,but the wavelength sensitivity is far from comparable with that of prism-coupled surface plasmon polariton(SPP).Herein,we propose and demonstrate an ultrasensitive angular interrogation sensor based on the transverse electric mode surface lattice resonance(SLR)mechanism in an all-metal metasurface.In theory,we derive the sensitivity function in detail and emphasize the refraction effect at the air-solution interface,which influences the SLR position and improves the sensitivity performance greatly in the wide-angle.In the measurement,a broadband light source substitutes the single-wavelength laser generally used in traditional angular sensing,and the measured SLR wavelength of broadband illuminant at normal incidence is defined as the single wavelength,avoiding the sensitivity loss from the large angle.The experimental sensitivity can reach 4304.35°/RIU,promoting an order of magnitude compared to those of SPP-sensors.This research provides a novel theory as well as the corresponding crucial approach to achieving ultrasensitive angular sensing.
基金National Natural Science Foundation of China(12004121,22202162)Natural Science Foundation of Fujian Province(2024J01080)+1 种基金Fundamental Research Funds for the Central Universities(ZQN-1006)Scientific Research Funds of Huaqiao University(605-50X19028)。
文摘Achieving the precise control over high-quality(Q)resonances,particularly bound states in the continuum(BICs),within plasmonic metasurfaces remains a substantial challenge due to inherent material losses,which can undermine the modulation efficiency and device performance in practical settings.Here,we introduce a mechanism,termed dual-channel-driven BICs,which exploits the cross-coupling between surface plasmon polaritons and guided mode resonances to enable the delicate formation and manipulation of high-Q bound states in dissipative plasmonic platforms.
基金supported in part by the National Institute of Health(NIH)U01CA279858,UO1CA284982,R01CA239078,RO1HL163513,R21CA267222,RO1CA264363.
文摘This review examines imaging-based nanophotonic biosensing and interferometric label-free imaging,with a particular focus on vesicle detection.It specifically compares dielectric and plasmonic metasurfaces for label-free protein and extracellular vesicle detection,highlighting their respective advantages and limitations.Key topics include:(ⅰ)refractometric sensing principles using resonant dielectric and plasmonic surfaces;(ⅱ)state-of-the-art developments in both plasmonic and dielectric nanostructured resonant surfaces;(ⅲ)a detailed comparison of resonance characteristics,including amplitude,quality factor,and evanescent field enhancement;and(ⅳ)the relationship between sensitivity,near-field enhancement,and analyte overlap in different sensing platforms.The review provides insights into the fundamental differences between plasmonic and dielectric platforms,discussing their fabrication,integration potential,and suitability for various analyte sizes.It aims to offer a unified,application-oriented perspective on the potential of these resonant surfaces for biosensing and imaging,aiming at addressing topics of interest for both photonics experts and potential users of these technologies.
基金supported by the Australian Research Council(Grant Nos.DP200101168 and DP210101292)the International Technology Center Indo-Pacific(ITC IPAC)via Army Research Office(contract FA520923C0023).
文摘We review the physics and some applications of photonic structures designed for the realization of strong nonlinear chiroptical response.We pay much attention to the recent strategy of utilizing different types of optical resonances in metallic and dielectric subwavelength structures and metasurfaces,including surface plasmon resonances,Mie resonances,lattice-guided modes,and bound states in the continuum.We summarize earlier results and discuss more recent developments for achieving large circular dichroism combined with the high efficiency of nonlinear harmonic generation.
基金This work was supported by the National Natural Science Foundation of China(91850113,11774115 and 11904271)the National Basic Research Program of China(2014CB921301)the Basic and Applied Basic Research Major Program of Guangdong Province(2019B030302003)。
文摘A harmonic vortex beam is a typical vector beam with a helical wavefront at harmonic frequencies(e.g.,second and third harmonics). It provides an additional degree of freedom beyond spin-and orbitalangular momentum, which may greatly increase the capacity for communicating and encoding information. However, conventional harmonic vortex beam generators suffer from complex designs and a low nonlinear conversion efficiency. Here, we propose and experimentally demonstrate the generation of a large second-harmonic(SH) vortex beam with quasi-nonlinear spin–orbit interaction(SOI). Highquality SH vortex beams with large topological charges up to 28 are realized experimentally. This indicated that the quasi-angular-momentum of a plasmonic spiral phase plate at the excitation wavelength(topological charge, q) could be imprinted on the harmonic signals from the attached WS2 monolayer. The generated harmonic vortex beam has a topological charge of l_(n)= 2 nq(n is the harmonic order). The results may open new avenues for generating harmonic optical vortices for optical communications and enables novel multi-functional hybrid metasurface devices to manipulate harmonic beams.
