Abstract This paper systematically investigated the factors affecting the coupling efficiency of a laser with a central wavelength of 4.65 μm into a chalcogenide glass anti-resonant hollow-core fiber. We analyzed critical parameters including the anti-resonant order, incident beam size, transverse offsets, and angular tilt. Our study revealed that optimal mode matching is achieved when the ratio of the input beam waist to the fiber's core radius is 0.78, which enables a theoretical maximum coupling efficiency of 97%. To validate these findings, we performed experiments with our self-developed chalcogenide glass anti-resonant hollow-core fiber. By implementing a novel bidirectional alignment technique, we demonstrated a record-high coupling efficiency of 76.7%. This experimental result is in agreement with the 85.4% efficiency predicted by our theoretical model, which was calibrated using the practical parameters of the fiber and light source. This research provides a dual contribution. It offers a quantitative theoretical framework for understanding coupling mechanisms and delivers a record-setting experimental result through an innovative design. This work provides essential theoretical guidance for building and optimizing related high-performance experimental systems.

Abstract Obtaining the optimal geometric parameters for a physical device is always a complex and time-consuming process. Aiming to improve the synthetic performance and design efficiency for permanent magnet eddy current coupling (PMECC), a Kriging-assisted multi-objective hierarchical optimization (KMHO) method is proposed in this paper. For the first time, the sensitivity and coupling degree are jointly adopted to stratify the design geometric parameters through the clustering method. Then, the Kriging model is employed to simplify the construction process of the optimization objective function in each layer. Next, the Multi-Objective Genetic Algorithm (MOGA) is used to maximize the output torque and minimize the axial force, and the volume is chosen as the optimal selection basis. Ultimately, the application results indicate that the proposed method can achieve satisfactory design outcome, and significantly reduce the design time, because a single cycle is sufficient for convergence. In addition, further analysis indicates the optimization results also take on excellent performance in nonrated operating conditions. Therefore, the method will provide a reference framework for multi-objective optimization design of other similar physical devices and instruments.

Reversible solid-state chromatic luminescence photoswitching in a dual-emitting MOF hybrid for advanced anticounterfeiting.

Dual heterojunction engineering on TiO2 enables the spatial decoupling of active sites, where holes mediate C-H activation and electrons drive O2 activation. This synergistic strategy achieves a remarkable C2 hydrocarbon production rate of 1.7 mmol g-1 h-1 with 83% selectivity and a remarkable 45-hour stability in the photocatalytic oxidative coupling of methane.

A comprehensive laser-induced plasma diagnostics of hafnium using fundamental and second harmonics of pulsed Nd: YAG laser.

The non-adiabatic quantum dynamics of four prototypical polycyclic aromatic hydrocarbons (PAHs) exhibiting anti-Kasha emission from the S2 state, i.e. 3,4-benzopyrene, 3,4-benzotetraphene, 1,12-benzoperylene and 2'-methyl-1,2-benzanthracene, has been investigated using the multiconfiguration time-dependent Hartree (MCTDH) method. While setting up a model linear vibronic coupling Hamiltonian, we introduce a novel parameter , which quantifies the energy gap between the Sm state at the Franck-Condon geometry and the Sn/Sm minimum energy crossing point of two diabatic states. This parameter serves as a versatile and easy-to-use tool for selecting the most relevant intrastate vibronic couplings and tuning normal modes Qi. The decay dynamics of the studied PAHs has been simulated following photoexcitation to either the first dark excited state (S1) or the first bright excited state (S2). The simulations reveal the dynamic equilibrium between the S1 and S2 states in the early time regime (up to 3 ps). Due to the exceptionally small S1-S2 energy gap and efficient electron-vibrational coupling between these states, molecules in the S1 state can transiently access the S2 state, sustaining a steady population in S2 that can fluoresce spontaneously in violation of the Kasha rule. These findings highlight the critical role of the interplay of the electronic energy gap and vibronic coupling in the excited-state dynamics of molecular systems exhibiting non-trivial anti-Kasha emission.

A platform is introduced to achieve ultra-strong coupling (USC) between light and matter using widely available materials. USC is a light-matter interaction regime characterized by coupling strengths exceeding 10% of the ground state energy. It gives rise to novel physical phenomena, such as efficient single-photon coupling and quantum gates, with applications in quantum sensing, nonlinear optics, and low-threshold lasing. Although early demonstrations in plasmonic systems have been realized, achieving USC in dielectric platforms, which offer lower losses and high Q-factors, remains challenging due to typically low mode overlap between the photonic field and the material resonance. Here, dielectric dual gradient metasurfaces supporting quasi-bound-states-in-the-continuum are leveraged to spatially encode both the spectral and coupling parameter space and demonstrate USC to an epsilon-near-zero (ENZ) mode in an ultra-thin SiO2 layer. The strong out-of-plane electric fields in tapered bar structure overlap exceptionally well with those of the ENZ mode, resulting in a normalized coupling strength of η = 0.10 and a mode splitting equivalent to 20% of the ENZ mode energy; a four-to-five-fold increase compared to previous approaches. The strong field confinement of the approach opens new possibilities for compact and scalable polaritonic devices, such as tunable frequency converters and low-energy optical modulators.

Graphdiynes are atomically thin carbon allotropes with mixed sp-sp2 hybridization, able to self-assemble into diverse 2D and 1D nanostructures, from atomic layers to nanoribbons and molecular wires, with tunable optoelectronic properties beyond those of graphene. Here, we investigate novel graphdiyne molecular wires obtained via Ullmann coupling of 1,4-bis(bromoethynyl)benzene molecules on Au(100) and Au(111) surfaces. Using scanning tunneling microscopy (STM) and low-energy electron diffraction (LEED), we track the structural evolution of these systems under increasing annealing temperatures. Exploiting Raman spectroscopy, we perform the first-ever in situ monitoring of the thermally activated transition from organometallic to covalent organic wires (OMW-to-COW), resulting in the assignment of specific Raman features to both phases supported, by density functional theory calculations. We demonstrate that surface orientation affects the Ullmann coupling efficiency, resulting in a lower OMW-to-COW transition temperature on Au(100) than on Au(111). These findings provide new insights into the temperature-dependent structural dynamics of graphdiyne molecular wires, enabling the development of more efficient on-surface synthesis processes and the design of novel functional carbon nanostructures for new-generation optoelectronic devices.

Enhancement of radiative coupling efficiency between out-of-plane excitonic emitters in an indium selenide (InSe) film and an integrated waveguide formed by silicon (Si) Mie-resonant nanodisks is experimentally studied.

Oxyallenes are valuable building blocks in organic synthesis, most commonly exploited as π-allyl metal precursors in transition-metal-catalyzed allylation reactions. In contrast, their engagement in radical processes remains largely unexplored. Herein, we disclose a Giese-type radical addition protocol in which acyl-substituted oxyallenes function as in situ precursors to α,β-unsaturated ketones, enabling efficient coupling with 2-azaallyl radicals. This metal-free method delivers a wide range of γ-amino ketones in high yields with broad functional group tolerance, mild conditions, and scalability to gram quantities. Mechanistic studies, including radical trapping and isotopic labeling, support a pathway involving radical addition of the 2-azaallyl radical to transient enone intermediates. These findings establish a new reactivity mode of oxyallenes in radical chemistry and provide an efficient route to synthetically and pharmaceutically valuable amino ketones.

Sensitive detection of carbendazim (CBZ), a widely monitored bactericidal pesticide globally, is critical to reduce risks to human health. In this study, Eu ions were embedded into a rigid metal-organic framework (MOF), to prepare Eu-MOF as a fluorescence signal source, which was subsequently post-modified with polyethyleneimine (PEI) for efficient coupling with anti-CBZ monoclonal antibodies (mAbs). On this basis, a PEI@Eu-MOF-mAbs fluorescent probe-based lateral flow immunosensor (LFIS) was developed for CBZ analysis, enabling dual-mode detection: rapid visual qualitative observation by the naked eye and intelligent fluorescence quantitative analysis by using a smartphone. PEI modification not only effectively improved the zeta potential, fluorescence intensity, quantum yield, and biological coupling ability of the Eu-MOF to mAbs, but also significantly enhanced the stability and anti-interference performance of PEI@Eu-MOF. The introduction of PEI@Eu-MOF-mAbs probes characterized by strong fluorescence emission, long fluorescence lifetime, and low background interference, markedly improved the detection sensitivity of the LFIS platform for trace CBZ. Under optimal conditions, the detection limit for smartphone-assisted fluorescence analysis was as low as 1.3 pg mL-1 with a wide linear detection range of 0.25-125 ng mL-1 for CBZ. The recoveries in spiked Panax notoginseng samples were 93.40-106.0% with RSD <1.69%, indicating outstanding reliability of the newly developed LFIS platform for accurate detection of CBZ. In comparison with seven other common pesticides, CBZ produced significantly weakened and stable fluorescence, indicating good specificity and stability of the developed platform over 4 weeks. Compared with current analytical methods, the smartphone-assisted PEI@Eu-MOF-mAbs dual-modal LFIS platform exhibited advantages of simple construction, easy operation, rapid response, obvious visualization to the naked eye, and intelligent quantitative analysis, highlighting its broad application potential for rapid screening and accurate point-of-care detection of CBZ in a large number of foods and agricultural products.

Coupled ionic-electronic effects offer intriguing opportunities for the development of next-generation memristive devices. Layered two-dimensional transition metal chalcogenides, in particular, enable controllable ion migration and efficient ionic coupling among devices, providing a promising platform for ion-regulated functionalities. However, repeated ion intercalation/deintercalation can cause structural degradation, limiting device stability. Here, we report a lithium-ion-regulated memristor based on hexagonal-phase VS2 nanoflakes, exhibiting reversible and highly linear conductance tuning. The device shows symmetric responses under periodic voltage pulses and achieves 32 stable conductance states with excellent retention and endurance. In situ transmission electron microscopy and Raman spectroscopy reveal that conductance modulation arises from a reversible crystalline-solid solution transition induced by lithium-ion intercalation/deintercalation, effectively suppressing structural degradation. Our work establishes a direct link between ion dynamics, lattice evolution, and electronic transport, demonstrating the potential of crystalline-solid solution processes for designing stable, high-precision ionic devices.

This work addresses the challenge of realizing broadband, low-loss fiber-to-waveguide coupling in the short-wavelength near-infrared range (700–1050 nm), where the required fine structural dimensions and taper tips approach or even exceed current fabrication limits, resulting in tight fabrication tolerances and degraded coupling efficiency. We propose a broadband trilayer adiabatic edge coupler on a thin-film lithium tantalate platform that requires only two standard lithography and etching steps. The design integrates a crossed bilayer taper and a dual-core mode converter to achieve adiabatic mode transformation from a ridge to a thin strip waveguide, ensuring excellent fabrication tolerance and process simplicity. Simulations predict a minimum coupling loss of 0.57 dB at 850 nm, which includes the transmission through the complete edge-coupler structure, along with a 0.5-dB bandwidth exceeding 140 nm. The proposed structure provides a broadband, low-loss, and fabrication-tolerant interface for short-wavelength photonic systems such as quantum photonics, biosensing, and visible-light communications.

Abstract BACKGROUND The simultaneous valorization of waste batteries, CO₂, and biomass holds significant importance for advancing a circular economy. RESULT In this work, valuable metals (Ni, Co, Mn) were recovered via an acid‐leaching and reduction method. These recovered metals were subsequently employed to in‐situ grow NiCoMn layered double hydroxide (LDH) on kaolinite (Kaol) nanosheets through a microwave‐assisted hydrothermal process. This strategy successfully constructs an S‐scheme heterojunction composite photocatalyst (NiCoMn‐LDH/Kaol) for the efficient coupling of photocatalytic CO₂ reduction with 5‐hydroxymethylfurfural (HMF) oxidation. Results demonstrated that the NCM‐LDH‐9/Kaol catalyst prepared at pH = 9 achieved the highest CO production rate of 235 μmol·g⁻ 1 ·h⁻ 1 and an exceptional 92.2% selectivity towards 2,5‐diformylfuran (DFF) from HMF oxidation under full‐spectrum irradiation. Mechanistic studies revealed that the S‐scheme heterojunction between LDH and Kaol significantly enhanced the separation of photogenerated charge carriers. Simultaneously, the oxidation of HMF provides the necessary protons for CO₂ reduction, establishing a synergistic enhancement. CONCLUSION This work presents a novel strategy for the high‐value utilization of spent batteries and the coupled conversion of biomass and CO₂, offering dual environmental and energy benefits. © 2025 Society of Chemical Industry (SCI).

Organic electrochemical synaptic transistors (OESTs) have gained attention as attractive platforms for nonvolatile artificial synapses, enabled by their low-voltage operation and efficient ion-charge coupling. While most existing studies have focused on modulating the electrolyte-semiconductor interface to maintain anion doping states in organic semiconductors, the influence of cations on anion doping states and synaptic performance remains largely unexplored. In particular, despite extensive research on electrolyte composition, cation-driven strategies for regulating ion diffusion and stabilizing doping states have not been systematically developed. Here, an effective strategy is proposed to improve anion-doping retention by tailoring the molecular structure of cations. Our results indicate that cation-anion interactions critically affect doping stability and diffusion kinetics. Electrochemical analyses combined with density functional theory (DFT) calculations demonstrate that the side-chain structure of cations can actively regulate the doping profile within the polymer semiconductor. The resulting devices exhibit enhanced synaptic retention and more linear long-term potentiation/depression (LTP/D) behavior. Furthermore, artificial neural network (ANN) simulations using a modified MNIST data set achieved a high recognition accuracy. These findings suggest a potential approach for controlling anion doping through cation design.

Abstract This study examines burst laser-induced pitting (BLIP), an understudied surface modification phenomenon driven by ultrafast laser bursts with sub-picosecond to picosecond inter-pulse delays. Through SEM and AFM analysis, we characterize BLIP as sub-micron pits with polarizationdependent oval shapes, alongside high-fluence melting zones and localized ripple-like structures. Unlike conventional LIPSS, BLIP demonstrates exceptional energy coupling efficiency, evidenced by 10× greater damage areas and a steeper fluence-scaling expansion rate than LIPSS, attributed to transient carrier-mediated processes. Pit density decays exponentially with delay (τ ≈ 6.6-8.9 ps), matching the timescale of self-trapped exciton (STE) relaxation, while spatial statistics reveal a delay-driven transition from field-guided ordering (1-5 ps) to randomized distributions (&gt;10 ps). The resonant-like angular distributions and delay-dependent ellipticity reduction indicate competing mechanisms: optical field enhancement dominates at short delays, while energy dissipation and structure disordering prevail at longer delays. Simulation of nanoplasma excitation reveals near-field optical field enhancements responsible for the ellipticity and ripple-like structures. Beyond their fundamental significance, these BLIP nanostructures offer practical functionalities, including use as anti-reflection coatings and hydrophobic surfaces. These findings establish BLIP as a new paradigm in ultrafast laser-material interactions, where burst parameters selectively activate defect-mediated or field-driven modification pathways in dielectrics.

Abstract Beam quality is a fundamental aspect for evaluating the performance of laser sources. M 2 -measurements serve as the gold standard for beam quality assessment since the 1990s. The measured M 2 parameter indicates similarity to the pure fundamental Gaussian mode, characterized by the ideal M 2 , by describing a beams' divergence. M 2 -values close to 1 are considered to correspond to nearly fundamental sources. However, in terms of the higher-order mode contribution of a laser, it does not permit a quantitative statement. Here, we introduce a framework to assess the fundamental mode content of a laser beam using M 2 -measurements and establish a direct link between beam quality and its mode composition by deriving a lower and upper bound to the fundamental mode's power in dependence of the measured M 2 -values. This result significantly enhances the utility of M 2 -measurements in evaluating laser sources, coupling efficiencies, focusing performance, and long-distance propagation, yielding a novel approach for characterization of light sources in fields like atomic, molecular and optical physics, quantum optics and the photonics industry. Given that the M 2 formalism underlies ISO 11146-1, our results may help guide future improvements of the standard toward mode-purity-based beam quality specifications.

Abstract Photocatalytic coupling of monofunctional molecules offers an atom-efficient route for the synthesis of value-added bifunctional organic compounds, yet its efficiency is significantly limited by the reverse reaction of radicals. Our density functional theory (DFT) calculations have indicated that a unique structure of partially exposed Pt encapsulated by a titanium oxide overlayer could intrinsically facilitate the desorption and suppress re-adsorption of reactive radicals, hence impeding the reverse reaction in the photocatalytic acetonitrile coupling reaction. A TiO2−x/Pt inverse heterostructure has then been developed via strong metal-support interaction (SMSI) with tunable TiO2−x coverage. Among the catalysts, an optimal partially encapsulated TiO2−x/Pt catalyst achieves a marked formation rate of succinonitrile of 8.41 mmol·gcat−1·h−1 from acetonitrile, reaching a 67.3% radical-to-product efficiency and a 5.6% apparent quantum yield, representing 3-fold enhancements over a conventional Pt-supported TiO2 catalyst, over 1.9-fold higher than bare Pt/TiO2 or fully encapsulated counterparts, respectively. Kinetic investigations demonstrate that the suppression of radical-proton recombination plays a more dominant role in the overall coupling performance compared to the radical initiation. This work underscores the critical role of tailored catalysts by coating with oxide domains to mitigate reverse reactions and establishes an effective strategy for advancing the efficiency in photocatalytic coupling.

Microbial energy conversion refers to the process of converting raw materials such as organic matter (sugars, acids, waste biomass, organic wastewater, etc.) or inorganic substrates (carbon dioxide, ammonia, sulfides, etc.) into renewable energy products, such as hydrogen, methane, ethanol, and electrical energy, through microbial metabolic processes. With the rapid development of synthetic biology and enzyme engineering, researchers can perform targeted modifications on microorganisms and their functional enzyme systems, thereby enhancing the conversion efficiency of substrates to energy products. However, in practical applications, microbial energy conversion still generally faces common bottlenecks such as limited electron transfer, complex metabolic regulation, and low energy conversion efficiency, which severely restrict the energy efficiency improvement and engineering promotion of the system. Iron-based materials, with excellent electron transfer ability, potential as enzyme cofactors, and good magnetic separation performance, are widely used in microbial energy conversion to synergistically improve the energy conversion efficiency and operational stability of the system. This paper systematically reviews the research progress in the applications of iron-based materials in representative microbial energy conversion technologies (such as hydrogen production, methane production, electricity production, ethanol production, and lipid production) and analyzes the key mechanisms by which different types of iron-based materials promote microbial energy conversion. This paper aims to provide theoretical support and technical reference for the construction, optimization, and practical application of efficient iron-based material-microbial coupling systems.

ABSTRACT Rapidly varying wavefront distortions impose a critical challenge to free‐space optical communication and in vivo imaging, which highlights the urgency of real‐time and high‐fidelity wavefront compensation. Deep‐learning‐based wavefront shaping offers a powerful tool to alleviate wavefront distortion. In this work, single‐shot‐based wavefront distortion recognition and compensation are realized by developing a retrieval neural network with digital twin generated data. The network can simultaneously predict the incoming distortions with speckles of the current frame. In a dynamic distortion channel, the wavefront transmission fidelity is significantly improved from 0.14 to 0.76 and the single‐mode‐fiber coupling efficiency of the transmitted field approaches (53 ± 3)% with single‐shot compensation. This work alleviates the burden of experimental data acquisition, offers a potential real‐time distortion correction technique and paves the way for quantum communication and biological imaging in dynamic complex environments.