Now showing1 - 9 of 9
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    Spectral sensing at a glance
    (Nature Publishing Group, 2026-10-14)
    Portable biosensors are revolutionizing the way we diagnose disease and ill-health. By varying a metasurface’s geometry continuously across a chip, a recent study by H. Kim et al. reports a new sensing strategy, which reads signals from individual camera images without the need for a spectrometer. This enables the label-free detection of biomarkers in a handheld format.
    Publicationtype: Journal Article
      13  8
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    Metasurfaces for the nanoscale engineering of light–matter coupling
    (Nature Publishing Group, 2026-10-05) ; ; ; ;
    Metasurfaces are planar, ultrathin arrays of subwavelength nanostructures that provide unprecedented control over optical fields. Initially demonstrated for wavefront shaping in beam steering and holography, metasurfaces are now recognized as a versatile platform for engineering light–matter interactions over broad spectral ranges. This Review surveys how the synergy between structured geometries and material excitations enables metasurfaces to act as a common photonic framework for concentrating light into deeply subwavelength volumes, substantially amplifying optical emission, interaction strengths and nonlinear responses, and giving rise to hybrid light–matter states known as polaritons. We first provide a comprehensive overview of relevant resonance mechanisms and coupling regimes before describing the predominant material excitations (plasmonic, excitonic and phononic). For each, we highlight unifying design principles, the resulting diversity of physical phenomena and the fundamental opportunities and limitations posed by metasurface integration. We close by outlining emergent directions and opportunities for the field, including tailored symmetries as well as topological and quantum metasurfaces.
    Publicationtype: Journal Article
      23
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    Fostering cultural change in research through innovative knowledge sharing, evaluation, and community engagement strategies
    (Nature Publishing Group UK, 2026-09-04) ;
    Sheu, Jinn-Kong
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    ; ;
    Alú, Andrea
    Bringing together researchers, funders, industry partners, and publishers from 14 countries across five continents, we advance the debate around open-science, assessment and learning. We introduce an integrative “open-knowledge system” framework linking knowledge production, validation, assessment, and reuse into one ecosystem view, and translate it into actionable recommendations for each stakeholder. Shifting focus to modular, machine-readable knowledge objects, these recommendations are intended to help diagnose misaligned incentives and guide reforms that properly value all scientific contributions.
    Publicationtype: Journal Article
      19  11
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    Polaritonic quasi-bound states in the continuum in individual van der Waals nanoantennas
    (SPIE, 2026-07-20)
    Ding, Qi
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    ; ; ;
    Kühner, Lucca
    The study of strong light–matter interaction in van der Waals (vdW) materials is at the forefront of current research in physics and chemistry, and it can be enhanced dramatically by employing optical resonances. Here, we report on the first observation of quasi-bound states in the continuum (qBICs) realized via polaritonic interfering resonances in isolated WS2 nanodisks. We validate experimentally the existence of polaritonic qBICs driven by the intrinsic coupling of Mie resonances and vdW excitons. We observe exceptionally strong light–matter interaction with a measured Rabi splitting approaching 270 meV – the largest reported value among all transition metal dichalcogenide self-hybridized systems to date. The giant coupling strength stems from qBIC-induced in-plane field enhancement, which strongly interacts with in-plane excitonic dipoles while suppressing radiative losses. Polarization-controlled measurements further demonstrate selective excitation of qBIC through switching incident polarization to specific orthogonal configurations. The observed polarization-dependent coupling provides an additional degree of freedom to control the hybrid states’ spectral characteristics and spatial field distributions. Our demonstrations provide a pathway for engineering high-quality light–matter hybrid states in compact nanostructures, with potential applications in on-chip photonics, polaritonics, and quantum optics.
    Publicationtype: Journal Article
      22  5
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    Exceptional broadband absorption of nanoporous gold explained by plasmonic resonances at dangling ligaments
    (Optica Publishing Group, 2026-07-13) ; ; ; ;
    Nanoporous gold (npAu) has emerged as a potential candidate for many optical applications, exploiting its large surface-to-volume ratio and high broadband absorption. However, the physical origin of its enhanced visible and near infrared absorption remained unclear and was rather explained by simplified phenomenological models. Here, we have employed leveled-wave approximants to simulate the optical response of realistic npAu structures. First, our simulations reproduced well the experimental absorption spectra. Second, we identify multiple resonances in the gaps between dangling ligaments that occur at the top and bottom surfaces of npAu films as the key contribution to the broadband absorption. These resonances at the surface of npAu cannot be captured by bulk effective medium models and should be considered separately as a surface effect. The additional absorption due to dangling ligaments contributes up to 80% to the overall absorption of npAu. Our results provide deeper insights into the absorption behavior of npAu, indicating promising avenues for photocatalysis and sensing applications.
    Publicationtype: Journal Article
      13
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    Harnessing loss for Q-modulated biosensors
    (Nature Research, 2026-07-02) ;
    A new nanophotonic sensing strategy converts even subtle refractive-index changes into large intensity variations via radiative Q-factor modulation. Implemented in a bound-state-in-the-continuum (BIC) metasurface, the concept enables ultrasensitive and scalable biosensing of only a few tens of tumour extracellular vesicles within 15 minutes.
    Publicationtype: Commentary
      33
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    An on-chip programmable valley optoelectronic nanocircuit
    (Nature Publishing Group, 2026-05-25) ;
    Xing, Kaijian
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    Zhai, Wenhao
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    ;
    In transition metal dichalcogenides, the valley degree of freedom directly couples valley-polarized excitons, excited by circularly polarized light to valley-dependent chiral photons, enabling ultrafast light-driven valleytronics. However, achieving fully integrated valley optoelectronics, incorporating on-chip in situ generation, selective routing and electrical readout of valley-dependent chiral photons, remains an unresolved challenge. Here we present a valley-driven hybrid optoelectronic nanocircuit that integrates chirality-selective meta-waveguide photodetectors with transition metal dichalcogenides. At room temperature, our purposely designed meta-waveguide device generates near-unity valley-dependent chiral photons in the second-harmonic generation from an encapsulated tungsten disulfide monolayer and selectively couples them to unidirectional waveguide modes, achieving an exceptional polarization selectivity of 0.97. These valley-dependent waveguide modes were subsequently detected by atomically thin few-layer tungsten diselenide photodetectors, exclusively responsive to the above-bandgap upconverted photons, thereby enabling all-on-chip processing of valley-multiplexed images. Our demonstration bridges a critical gap in lightwave valleytronics, paving the way for compact, programmable and scalable valley information processing and fostering the development of light-based valleytronic quantum technologies.
    Publicationtype: Journal Article
      41
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    Integration of 2D materials in radial van der Waals heterostructure metasurfaces
    (American Chemical Society (ACS), 2026-05-21) ; ; ; ;
    Two-dimensional semiconductors, such as monolayer transition metal dichalcogenides (TMD), exhibit strong excitonic transitions at room temperature and offer a platform for exploring light-matter interactions in nanoscale photonic systems. In this work, we demonstrate a compact and polarization-invariant photonic metasurface, fabricated from hexagonal boron-nitride (hBN) and based on radial bound states in the continuum (BIC), which are formed by radially distributed pairs of structurally asymmetric resonators. The metasurface employs multiple symmetry-breaking perturbations to support high-quality (Q) factor resonances within a radial footprint of 4.5 μm – approximately one-sixth of the area of previous hBN BIC metasurface implementations based on large periodic arrays. Compared to these approaches, the radial geometry furthermore achieves sizable Q-factors with a reduced footprint. By integrating the hBN photonic structure with a WS2 monolayer, we observe enhanced photoluminescence when its resonance is spectrally aligned with the exciton resonance, accompanied by signatures of discrete momentum-space patterns that identify the orbital-angular-momentum-carrying ring eigenmodes. These features persist over a wide range of excitation powers and show minimal linewidth broadening, indicating robust and spatially modulated exciton-photon coupling. This work establishes a scalable approach for generating hybrid photonic-excitonic states with momentum-space structure, offering opportunities for exciton localization, valley emission, spatially programmable light-matter interaction in 2D material platforms and compact luminescent devices based on 2D material integrated metasurfaces.
    Publicationtype: Journal Article
      31  11
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    Tunable polaritonic topologies generated by non-local photonic modes
    (Nature Publishing Group, 2026-05-12) ; ; ; ;
    Schwab, Julian
    Photonic skyrmions are topological textures that exhibit remarkable resilience to environmental perturbations and support deeply subwavelength features, making them promising candidates for high-resolution microscopy, optical computing devices and ultrahigh-density information encoding. However, in contrast to free-space optical skyrmions, all existing approaches to generate polaritonic field skyrmions are limited by a lack of dynamic tunability. In general, without engineering the phase of the incident light, both their lattice site diameter and total topological charges remain fixed after fabrication. These constraints originate from a shared reliance on wavelength-dependent coupling structures or complex excitation conditions. To overcome these limitations, we introduce the concept of dynamically controllable polaritonic topologies generated by non-local photonic modes. Here we leverage quasi-bound states in the continuum resonances in dielectric metasurfaces to launch hyperbolic phonon polaritons in hexagonal boron nitride that interfere to create highly confined photonic skyrmion lattices with diameters down to 271 nm (λ/25). Thanks to the steep dispersion of hexagonal boron nitride, we can change the excitation frequency to achieve control over the size of individual photonic skyrmions within the same physical resonator structure. In addition, our platform is not limited to one type of topology but can generate optical meron lattices and kπ-twist skyrmions through straightforward variations in resonator shape, providing a feasible path towards skyrmion multiplexing and near-arbitrary topologies. The synergistic integration of resonant metasurfaces with polaritonic topologies has potential applications for nanophotonics, such as topological lasing, nonlinear optics and twistronics, as well as for condensed matter physics, such as Chern insulators and topological edge states.
    Publicationtype: Journal Article
      40  10