Objective Chiral metasurfaces capable of discriminating between left-and right-handed circularly polarized light (LCP and RCP) are of great significance for polarization optics, enantio-sensitive detection, and integrated photonic devices. However, the optical activity of natural chiral materials is intrinsically weak, and most artificial chiral metasurfaces require complicated three-dimensional architectures or multilayer stacking, which increase fabrication difficulty and limit scalability. To address these challenges, this work introduces an origami-inspired nanohole array metasurface that enhances circular dichroism (CD) through a simple folding transformation. The objective of this study is to demonstrate a compact, low-cost, and tunable chiral platform that achieves strong CD and provides new physical insights into geometry-induced chirality. Methods The proposed metasurface is constructed from a gold film perforated with a periodic array of bar-shaped nanoholes. In its planar state, the structure preserves mirror symmetry and thus exhibits negligible CD. By introducing a single folding step along the unit-cell axis, mirror symmetry is broken, creating a quasi-three-dimensional geometry. The optical response is numerically investigated using the finite-difference time-domain (FDTD) method. Transmission spectra under left-and right-circularly polarized light are simulated for both unfolded and folded configurations. The CD spectra are obtained by calculating the difference in transmission between LCP and RCP components. A series of parameter studies is conducted to assess the influence of folding angle, film thickness, and aperture geometry on the CD response. Specifically, the folding angle beta is varied from-80 degrees to +80 degrees, the gold film thickness is adjusted between 10 and 40 nm, and the aperture length and width are tuned to evaluate their impact on coupling efficiency. In addition, a theoretical framework based on Jones matrix formalism is established. The full transmission matrix is reconstructed from co-polarized and cross-polarized transmission amplitudes and converted into the circular basis, yielding theoretical CD spectra that are directly compared with FDTD simulations. Results and Discussions Numerical simulations demonstrate that the folded metasurface exhibits a dramatic enhancement of optical chirality compared with the planar case. The CD spectrum of the folded structure reaches a maximum value of 0.58 at 621 nm and shows an opposite-sign resonance at 739 nm, corresponding to dual-wavelength selective absorption. This dual-band feature indicates strong discrimination between circular polarizations, providing additional degrees of freedom for optical functionality. The folding angle beta plays a decisive role in determining the magnitude of chirality. CD increases steadily with beta, with optimal performance observed near 45 degrees , where structural asymmetry is maximized. Variations in the inclination angle alpha further confirm that geometric perturbations of the nanohole orientation strongly influence polarization-dependent responses. Film thickness also exerts significant influence. At 20 nm, the metasurface exhibits the strongest CD, while increasing thickness to 40 nm reduces the CD value due to enhanced multiple scattering and reflection. This trend is further illustrated by electric-field distribution maps, which reveal weaker near-field localization at larger thicknesses. Aperture geometry contributes an additional tuning mechanism. Changes in the hole length a have only minor effects, whereas widening the hole significantly alters the magnitude and spectral position of the CD peaks, highlighting the sensitivity of coupling efficiency to lateral dimensions. The Jones matrix analysis provides clear physical insight into the enhancement mechanism. The amplitudes of the four matrix elements reveal large off-diagonal terms, signifying strong cross-polarization conversion. The phase differences between matrix components reveal pronounced phase mismatches that amplify polarization-dependent interference. As a result, the theoretical CD spectrum reconstructed from the matrix exhibits peaks and troughs closely aligned with those obtained by simulation, validating the model. These results confirm that the observed chirality enhancement originates from the interplay of strong cross-polarization coupling and phase delay between orthogonal modes. To further benchmark the proposed design, we summarize representative chiral metasurfaces reported in recent years, including planar asymmetric patterns, twisted bilayers, all-dielectric structures, and toroidal-mode metasurfaces. Compared with these approaches, the origami nanohole array achieves one of the highest CD values (0.58) while maintaining structural simplicity and requiring only a single folding operation. Importantly, the structure exhibits dual-wavelength selectivity and geometrical tunability via folding angle adjustment, which are not simultaneously available in most previously reported devices. Conclusions This study demonstrates that an origami-inspired nanohole metasurface can achieve strong and tunable chiral responses with simplified fabrication. A maximum CD of 0.58 at 621 nm and an opposite resonance at 739 nm confirm its dual-wavelength selective capability. Systematic parameter analysis highlights the roles of folding angle, film thickness, and aperture geometry in tailoring the spectral response. Theoretical predictions based on Jones matrix formalism are consistent with numerical simulations, confirming that enhanced cross-polarization coupling and phase mismatch drive the CD amplification. Beyond theoretical validation, the design offers distinct practical advantages over traditional chiral metasurfaces. Its single-step folding operation reduces fabrication complexity and cost, making it more compatible with large-area processing. Nevertheless, challenges such as maintaining folding-angle precision, ensuring large-area uniformity, and guaranteeing structural stability must be addressed before practical implementation. Future research may explore multi-fold or multilayer origami configurations and employ advanced nanofabrication strategies to further enhance performance. Overall, the origami metasurface provides a promising and effective pathway toward low-cost, reconfigurable, and high-performance chiral devices for applications in chiral sensing, polarization control, and integrated photonics.

In light of large annual output and easy gathering, expired foods are regarded as a potential biomass to produce high value-added carbon cathodes in large scale for Zn-ion hybrid supercapacitors (ZIHSCs). Herein, inspired by the composition rich in protein and spongy scaffolding framework, the recycled carbon source of expired waffles is converted into 3D cheese-like hierarchical porous carbon doped by N, O dual-heteroatoms, together with high surface area and ample interconnected multiscale channels, plentiful nano-sized graphene layers plus preferable wettability towards aqueous electrolyte, therefrom making for numerous accessible active sites, fast kinetics and robust 3D network. As a result, the assembled aqueous coin-type ZIHSC device achieves a wondrous capacity of 214.4 mAh g- 1 at 0.1 A g- 1 with a marvelous conserved capacity of 94.7 mAh g- 1 by magnifying the current density to 50 A g- 1 and irresistible energy/power outputs of 171.2 Wh kg-1/42 kW kg- 1 plus an illustrious durability of 95.6 % capacity conservation over 20000 cycles at 20 A g-1. Significantly, the assembled quasi-solid ZIHSC device gives a surprising energy storage capability (a capacity of 154.9 mAh g-1, an energy output of 121.0 Wh kg-1, along with excellent flexibility and a low self-discharge rate of 2.75 mV h-1).

In this study, we propose and analyze a highly efficient scheme for realizing sensitive mass sensors in a quadratically coupled optomechanical system, assisted by a gain cavity via a nonlinear second-order sideband process. Moving beyond conventional linearized approximations, we derive analytical expressions for both the second-order sideband efficiency and mass-sensing sensitivity using a perturbation approach. Our scheme enables mass detection by monitoring shifts in the second-order sideband generation efficiency when a target mass is deposited on the dielectric membrane. Using experimentally feasible parameters, we identify the maximum achievable efficiency of the second-order upper sideband and its corresponding optimal sensitivity. Remarkably, with the aid of a gain cavity, both the sideband efficiency and mass sensitivity are significantly enhanced-particularly near the exceptional point, where improvements exceeding three orders of magnitude are demonstrated. This work provides a promising approach to high-precision mass measurement, advancing and complementing existing methodologies.

We propose an external cavity laser based on a nanobeam cavity and RSOA for sensing. The detection limit of the refractive index change is improved by a factor of 175 compared to its passive counterpart.

The three-mode coupling among excitons-surface plasmon(SP)-excitons has attracted extensive attention owing to its richer modulation capability compared to traditional two-mode coupling. However, the coupling mechanism of middle hybrid state in three-mode systems has not been clear. Here, we develop a full quantum theory based on the Jaynes–Cummings model to investigate the properties of middle plexciton branch (MPB) in excitons-SP-excitons system. The calculated scattering spectrum includes three plexciton branches, which shows that the MPB has the narrowest linewidth and lowest peak amplitude compared to the other two branches. The derived Hopfield coefficients demonstrate that the narrowest linewidth of MPB is due to its low SP fraction compared to that of excitons, which is different from the fractions of SP and excitons for the other two branches. The calculated results indicate that MPB peak amplitude is lowest because the detuning between two excitons is smaller than the coupling coefficient g, and MPB has the lowest population compared with those of the other two branches. Additionally, to verify our theory, we design an Au nanorod coated with two layers of J-aggregate nanoshells by the finite-difference time-domain(FDTD) simulation which results accord well with our theory. Our work has wide applications in quantum optical devices, quantum information, and quantum computing.

Abdominal aortic aneurysms (AAAs) involve localized dilation of the abdominal aorta, with the reversal of this condition being significantly limited by the inherently poor and abnormal regenerative repair of the aortic elastic matrix. Mesenchymal stem cell exosomes (MSCEs) are promising regenerative tools; however, achieving precise targeting of AAA with MSCEs is challenging owing to the high blood flow in the arterial system. In this study, an engineered exosomal nanomotor is developed for magnetic and chemical propulsion. The results demonstrate that this nanomotor effectively enhances the delivery of MSCEs to the AAA through magnetic field navigation and catalase-induced chemotaxis. The nanomotor significantly enhances the elastic matrix repair, reduces oxidative stress, and activates the PI3K/Akt pathway, leading to aneurysm shrinkage and reversal. In addition, the nanomotor possesses magnetic resonance imaging capabilities. The use of this nanomotor offers a novel, targeted drug delivery system in a rat model of AAA and holds promise as a potential therapeutic option for this condition.

One-way photonic devices are based around the concept of directionally-dependent propagation of light that can be used in the design of optical circuits. We demonstrate a straightforward method arising from cascade lasing transfer using a pair of coupled microcavities. The concept is based on consecutive down-converted laser transmission leading to net cross-cavity propagation in one direction. To describe this system, we first develop a simple, generalized coupled-cavity rate equation model to calculate the efficiency of the lasing cascade process. The basic idea is then demonstrated experimentally using a coupled resonator geometry. The two-cavity lasing design forms a basic three-wavelength microdevice that can change the original lasing wavelength or act as a one-way down-converting micro-lasing system.

Owe to the ability of supporting propagating surface plasmons, silver nanowire can be decent candidate as optical nanoantenna to modulate the polarization property of nano-emitters. Here, we created a quantum dots and silver nanowire coupling system to implement the controllable polarization dependence of this antenna effect. Several basic modes are mainly explored with both positive and negative excitation and observation directions. For the contrast excitation directions, both the center and the end fluorescence spots have reverse polarization dependence characterizations. While the controllable polarization dependence only appears at the center spot for the different observation angles. Based on these modes, diverse polarization dependence properties can be extended flexibly. The reasons for the phenomena are explained using the theoretical simulation. The numerical calculation shows the silver nanowire can act both optical receiving antenna and transmitting antenna in this process. Achieving on the controllable polarization dependence, our results are useful in the investigation about the coupling of nano-emitters and optical antenna.

Oxygen-containing functional groups in functionalized biochar (BC) play an important role in its environmental applications. Herein, we introduced oxygen atoms into BC by copyrolysis of sawdust and magnesium carbonate basic pentahydrate (MgCO3)(4)center dot Mg(OH)(2)center dot 5 H2O for the preparation of O-enriched porous BC (OPBC). OPBC800 (OPBC pyrolyzed at 800 degrees C) exhibited ultrahigh activity to activate ferrate (K2FeO4) for the oxidation of sulfadiazine (SDZ, 100% removal of SDZ in 2 min at pH = 5). We found that SDZ molecules can be rapidly adsorbed by the hierarchical porous structure of OPBC and were expediently oxidized by in situ generated Fe(IV) and Fe(V) active species on the surface of OPBC. The degradation mechanism of SDZ involved is quite different from the well-confirmed mechanism in which only active species in the solution play a role. Electrochemical impedance spectroscopy showed that O-doping in OPBC improved the electron-donating ability and expedited the electron transfer to ferrate, thus enhancing the catalytic activity of OPBC. This provides a new functionalization method for BC and provides more information about the activation of ferrate.

Background Bone defects remain an unsolved clinical problem due to the lack of effective osteogenic induction protocols. Nanomaterials play an important role in bone defect repair by stimulating osteogenesis. However, constructing an effective bioactive nanomaterial remains a substantial challenge. Methods In this study, mesoporous silica nanoparticles (MSNs) were prepared and used as nanocarriers for basic fibroblast growth factor (bFGF). The characteristics and biological properties of the synthetic bFGF@MSNs were tested. The osteogenic effects of the particles on the behavior of MC3T3-E1 cells were investigated in vitro. In addition, the differentially expressed genes during induction of osteogenesis were analyzed by transcriptomic sequencing. Radiological and histological observations were carried out to determine bone regeneration capability in a distal femur defect model. Results Achieving bFGF sustained release, bFGF@MSNs had uniform spherical morphology and good biocompatibility. In vitro osteogenesis induction experiments showed that bFGF@MSNs exhibited excellent osteogenesis performance, with upregulation of osteogenesis-related genes (RUNX2, OCN, Osterix, ALP). Transcriptomic sequencing revealed that the Wnt/β-catenin signalling pathway could be activated in regulation of biological processes. In vivo, bone defect repair experiments showed enhanced bone regeneration, as indicated by radiological and histological analysis, after the application of bFGF@MSNs. Conclusion bFGF@MSNs can promote bone regeneration by activating the Wnt/β-catenin signalling pathway. These particles are expected to become a potential therapeutic bioactive material for clinical application in repairing bone defects in the future.

Objective: Single-mode operation is very important for laser emissivity; to exceed the emissivity of a single laser, the phase locking of all lasers in an array can be achieved only when the laser array is coupled and operated in single-mode. Methods: In this study, a single-mode laser emitted along the waveguide was realized through cross-coupling microspheres connected to a straight waveguide. Whispering-gallery modes were formed at the equators of the two microspheres when their resonance conditions were simultaneously satisfied. Compared with a single microcavity, the FSR of the coupled microcavities was significantly increased owing to the Vernier effect. Moreover, when the waveguide was coupled with the microspheres in the weak field of the resonance modes, the whispering-gallery modes near the equator were significantly suppressed, and a new quadrilateral mode was formed. Result: The energy in the coupling microspheres was concentrated in the stable quadrilateral mode and the Q factor was high (similar to 10(4)). The single-mode laser energy in the waveguide accounted for 82 % of the total optical radiation energy of the device. This work has application prospects in laser switches and on-chip light sources.

Large bone defects remain an unsolved clinical challenge because of the lack of effective vascularization in newly formed bone tissue. 3D bioprinting is a fabrication technology with the potential to create vascularized bone grafts with biological activity for repairing bone defects. In this study, vascular endothelial cells laden with thermosensitive bio-ink were bioprinted in situ on the inner surfaces of interconnected tubular channels of bone mesenchymal stem cell-laden 3D-bioprinted scaffolds. Endothelial cells exhibited a more uniform distribution and greater seeding efficiency throughout the channels. In vitro, the in situ bioprinted endothelial cells can form a vascular network through proliferation and migration. The in situ vascularized tissue-engineered bone also resulted in a coupling effect between angiogenesis and osteogenesis. Moreover, RNA sequencing analysis revealed that the expression of genes related to osteogenesis and angiogenesis is upregulated in biological processes. The in vivo 3D-bioprinted in situ vascularized scaffolds exhibited excellent performance in promoting new bone formation in rat calvarial critical-sized defect models. Consequently, in situ vascularized tissue-engineered bones constructed using 3D bioprinting technology have a potential of being used as bone grafts for repairing large bone defects, with a possible clinical application in the future.

As one of the indispensable instruments in many fields, optical tweezers are extensively utilized in micromanipulation. Vortex beams and diverse structured light fields make multi-trap optical tweezers possible. Here, the radiation forces of Laguerre-Gaussian (LG) composite vortex beams exerting on a Rayleigh dielectric particle are investigated. Our results show that the multi-trap optical tweezers can be produced by the Laguerre-Gaussian composite vortex beams, which can trap the particles with both high and low refractive indices in the focus plane at multiple positions. Moreover, by changing the orbital angular momentum (OAM) quantum numbers and energy ratios of the Laguerre-Gaussian modes participated in the superposition, the quantities of the optical traps and the distances between multiple traps can be conveniently adjusted. Our beams can be generated by several methods, which provides more convenience for the creation of multiple optical traps. The results presented in this work are potential in optical micromanipulation, as well as other applications in biology and chemistry.

Design of the low-cost and environmentally friendly catalyst for advanced oxidation processes is highly desired in environmental remediation. Herein, a flower-like CuFe2O4 nanostructure is synthesized by a self-templating method for the first time and used for the activation of peroxymonosulfate (PMS) to degrade carbamazepine (CBZ). The catalytic performance of the flower-like CuFe2O4 is much higher than that of the other CuFe2O4 structures (nanoparticles, bulk, and sphere). 90% of CBZ (10 mg/L) can be degraded by adding 0.1 g/L of CuFe2O4-16-350 and 0.2 g/L PMS, and 50% of TOC got removed in 120 min. After five consecutive cycles, the CBZ removal efficiency by the flower-like CuFe2O4 still remains at 66%. Kinetic behavior of CBZ degradation follows the pseudo-first-order reaction model, and the reaction rate constant value of the flower-like CuFe2O4 is 3.7 times higher than that of CuFe2O4 nanoparticles. The structure-dependent catalytic activity of CuFe2O4 catalysts is investigated by experiments and characterizations such as BET, XPS, and H-2-TPR. The results show that the excellent catalytic performance of the flower-like CuFe2O4 is mainly attributed to the strong interaction of dual metal species in it apart from its high specific surface area and large pore volume. A reasonable mechanism of PMS activation is established on the basis of the characterizations of catalyst, radical determination, and the identification of intermediates. This work provides a novel strategy to develop a highly efficient and stable spinel catalyst for pollutant degradation through PMS activation.

We theoretically report a strong light–matter interaction in a sandwich structure composed of hybridized inorganic–organic perovskite nanowires, silica (SiO 2 ) films and a silver (Ag) film. Surface plasmon effectively enhances the strong exciton–photon coupling strength of perovskite nanowires, which depends on reduction of effective mode volume and local field enhancement. By calculation, we find that the thicknesses of SiO 2 and Ag films can affect the coupling strength. With the suitable thickness of SiO 2 (5 nm) and Ag (30 nm) films, Rabi splitting can reach 319 meV, while without an Ag film Rabi splitting is only 270 meV. Furthermore, Rabi splitting shows a negative correlation with SiO 2 film thickness within a limited range. Still, it has a nonlinear relation with Ag film thickness because the imaginary part of the effective index for the hybridized mode shows a nonlinear relation with Ag film thickness. Our structure provides suitable parameters for the experiment and has potential application in nano-lasers.

In this work, we report an amplified strong coupling phenomenon in a hybridized nanowire. The hybridized nanowire structure is composed of CH3NH3PbBr3 perovskite nanowire coated by SiO2 film and silver film. Due to the existence of silver film, Rabi splitting in hybrid structure can reach 303.2 meV, while the Rabi splitting in a pure perovskite nanowire is only 236.4 meV. Also, thicknesses of SiO2 film and Ag film can control the Rabi splitting of hybridized structure: (i) the thicker the Ag film, the greater the Rabi splitting; (ii) the thinner the SiO2 film, the greater the Rabi splitting. Finally, index of SiO2 film shows a linear relation with Rabi splitting.

A microring resonator coated with a fluorescent high-refractive-index film provides a structure that supports whispering-gallery modes (WGMs) via the contrast in the refractive index. In the past, number, size, and refractive index of nanoparticles were analyzed by the degree of resonant mode splitting in the cavity. Compared with the small mode shift, this splitting is easier to detect and has strong anti-interference ability. However, there are several mechanisms for the mode splitting due to the different sizes of nanoparticles. The magnitudes of different mode splittings are quite different, which easily leads to confusion in spectral analysis. In this work, the mechanisms of resonant mode splitting are studied by the FDTD method combined with light field distributions and spectra. Field distributions of the symmetric mode and the asymmetric mode relative to the position of the nanoparticle for the fundamental order and second radial order were simulated. We first distinguished the splitting of the fundamental mode (~0.010 THz) due to the backscattering of the particles from the separation between the fundamental mode and the high-order mode (~1 THz) for the same particle (~100 nm). In addition, fundamental mode splitting was used to estimate the size and number of particles, and these sizes were consistent with those in the design. This work demonstrates the potential application of microring cavities based on WGMs in single particle detection.

Abstract Tailoring the fluorescence emission of quantum emitters to a desired direction is a crucial issue to achieve high efficient photodetection and realize unique optoelectronic devices. In this study, the directional emission of quantum dots controlled by optical traveling wave antennas based on 1D silver nanowires (NWs) was investigated. Both leaky waves and surface waves on a single NW are utilized for fluorescence emission control, and we show that the coupled fluorescence transforms from bidirectional to unidirectional emission when the surrounding medium changes from air to water. Moreover, in the unidirectional case, we obtain an ultra-narrow half-power bandwidth about 20°. Finite-difference time-domain simulations and Green’s function method in a stratified medium are used to calculate the far-field emission patterns of the hybrid structures, which agree well with the experiments. Further analyses based on typical modes and the dipole-chain model also reveal the mechanism behind the bidirectional and unidirectional fluorescence emission. These results show that the structures have great potential in integrated on-chip, sensing and photon-collection devices.