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N/S Co-modified carbon/Na3V2(PO4)3 is synthesized using a simple hydrothermal method and exhibits superior capacity and rate capability for Zn-ion storage.

Real-time, high-sensitivity, and label-free detection to single nanoparticles has been achieved via visualizing the interaction between surface plasmon polaritons (SPPs) and nanoparticles, which is widely applied to chemistry and biology. In this work, aiming to enhance the detection sensitivity to nanoparticles, we explore the interaction of SPP standing waves with single nanoparticles. Compared with SPPs, the inhomogeneous fields of SPP standing waves modulate charge distributions around the particle and excite different electric dipole modes that tailor localized enhancements. For nanoparticles situating at electric antinodes of SPP standing waves, a vertical electric dipole is excited and high-density charges are stimulated around nanoparticle-film nanocavities, leading to further increased localized enhancement. The localized enhancement experiences more increase with smaller particle size, lower dielectric constant of surrounding medium, and lower particle refractive index. Via tailoring the localized enhancement by SPP standing waves, the sensitivity of SPP microscopy can be improved, which would broaden its applications on nanotechnology, biomedicine, and environmental monitoring.

Plasmonic interferometric imaging has been widely used for fast and label-free detection to nano-objects, which associates the interference between launched and scattered surface plasmon polaritons (SPPs). As scattering of SPPs is affected by the characteristics of nano-objects, particle size, particle index and particle-interface distances have been retrieved from the imaging. Refractive index of dielectric, which tailors the resonant wavelength of launched SPPs, is also a key issue to plasmonic interferometric imaging. Yet, the influence of refractive index to plasmonic interferometric imaging has not been investigated. In this work, we connected the dielectric refractive index to the interferometric image intensity distribution, and found that both fringe periodicities and intensity profiles along SPP wavefronts were tailored by the refractive index, which is illustrated by using glucose solutions with different concentrations. Our research illustrates the pattern change of plasmonic interferometric imaging induced by dielectric refractive index, which not only paves the way for the basic understanding on the plasmonic interferometric imaging, but also provides a new potential visual method for real-time refractive index sensing and monitoring, which will be applied to food safety and environment monitoring.

Directionally scattered surface plasmon polaritons (SPPs) promote the efficiency of plasmonic devices by limiting the energy within a given spatial domain, which is one of the key issues to plasmonic devices. Benefitting from the magnetic response induced in high-index dielectric nanoparticles, unidirectionally scattered SPPs have been achieved via interference between electric and magnetic resonances excited in the particles. Yet, as the magnetic response in low-index dielectric nanoparticles is too weak, the directionally scattered SPPs are hard to detect. In this work, we demonstrate forward scattered SPPs in single low-index polystyrene (PS) nanospheres. We numerically illustrate the excitation mechanism of plasmonic induced electric and magnetic multipole modes, as well as their contributions to forward SPP scattering of single PS nanospheres. We also simulate the SPP scattering field distribution obtaining a forward-to-backward scattering intensity ratio of 50.26:1 with 1 μm PS particle. Then the forward scattered SPPs are experimentally visualized by Fourier transforming the real-space plasmonic imaging to k-space imaging. The forward scattered SPPs from low-index dielectric nanoparticles pave the way for SPP direction manipulation by all types of nanomaterials.

Plasmonic imaging has exhibited superiority in label-free and fast detection to single nanoparticles due to its high sensitivity and high temporal resolution, which plays an important role in environmental monitoring and biomedical research. As containing plenty of information associated with particle features, plasmonic imaging has been used for identifying the particle sizes, shapes, and permittivity. Yet, the effects of the nanoparticle features on plasmonic imaging are not investigated, which hinders the in-depth understanding to plasmonic imaging and its applications in particle identification. In this work, we analyzed five types of nanoparticles, including polystyrene (PS), Au, silicon nanospheres as well as PS and Ag nanowires. We illustrated the effects of nanoparticle sizes, shapes, and permittivity on spatial resolution, imaging contrast, and interference fringes. We found that nanoparticle sizes and permittivity influenced the imaging contrast. Via introducing size parameter relevant to interference fringes, the connection between particle shape and reduction rate of size parameter is built, and the effects of particle shapes on the interference patterns are revealed. Our research provides a basis for improving the plasmonic imaging and presents guidance for applications on particle identification in nano-detection, biosensor, and environmental monitoring.

Mass production of ordered and porous three-dimensional (3D) electrodes is a crucial prerequisite for practical energy storage devices. MXenes have drawn considerable attention as pseudocapacitive ...

An angle-interrogated surface plasmon resonance (SPR) sensor based on a prism-coupled configuration has been extensively applied in biomedicine, environment monitoring, and food safety. Yet, the low sensitivity and low spatial resolution impede its further development. In this Letter, we investigated objective-coupled locally excited SPR for refractive index (RI) sensing with high sensitivity and high resolution. Through theoretical analysis, the SPR angle was retrieved from back focal plane imaging, which was highly correlated to the RI of the surrounding medium. Experimentally, a RI sensitivity of 77.41° refractive index unit ( R I U ) − 1 was achieved with a detection range of 0.068 RIU when using glucose solutions for the demonstration. Furthermore, we acquired the spatial resolution of the configuration being 290 nm, and the RI measurement to a polydimethylsiloxane droplet with high spatial resolution was implemented. As a result, compared with the classical prism-coupled configuration, the locally excited SPR provides a method to achieve RI sensing with high sensitivity and high resolution.

Due to high sensitivity and temporal resolution, surface plasmon resonance microscope (SPRM) has been widely used in biological analysis. In this review, we briefly introduced the principle and setup of SPRM. Applications in label-free biological analysis are also indicated, including fast detection to single cells, exosomes, viruses, and molecules, as well as their dynamic behaviors. The limitations of SPRM are also depicted. The methods to improve the focus drift and low spatial resolution are illustrated. Two newly-developed microscopy techniques based on SPRM, i.e. plasmonic scattering microscope and electrochemical impedance microscope, are also described. Finally, a summary of SPRM technique and a bright future outlook is presented.

Simultaneous Interpreting (SI) as a profession has been gaining momentum in China, but little has been researched on Chinese professional conference interpreting on a basis of large quantity of empirical data. This study adopts an information-based SI fidelity assessment approach to probe into the propositional information loss in an SI corpus of seventeen English(B)-Chinese(A) simultaneous interpreters’ interpretations, and through stimulated retrospective interviews of three conference interpreters. Results show that operational constraints (concurrent listening and speaking, time constraint and incremental processing), source language factors (speed, information density, accent, linguistic complexity, technicality, etc) and interpreting direction (B to A), etc, account for typical propositional omission, incompletion or error.

By eliminating the photodamage and photobleaching induced by high intensity laser and fluorescent molecular, the label-free laser scanning microscopy shows powerful capability for imaging and dynamic tracing to biological tissues and cells. In this review, three types of label-free laser scanning microscopies: laser scanning coherent Raman scattering microscopy, second harmonic generation microscopy and scanning localized surface plasmon microscopy are discussed with their fundamentals, features and recent progress. The applications of label-free biological imaging of these laser scanning microscopies are also introduced. Finally, the performance of the microscopies is compared and the limitation and perspectives are summarized.

In order to address the present difficulty in experimentally generating the relativistic Laguerre-Gaussian laser, primarily due to damage caused to optical modulators, a high-reflectivity phase mirror is applied in the femtosecond petawatt laser system to generate a relativistic hollow laser at the highest intensity of $6.3\ifmmode\times\else\texttimes\fi{}{10}^{19}\text{ }\text{ }\mathrm{W}/{\mathrm{cm}}^{2}$ for the first time. A simple optical model is used to verify that the vortex laser may be generated in this new scheme; using such a relativistic vortex laser, the hollow plasma drill and acceleration are achieved experimentally and proven by particle-in-cell simulations. With the development of the petawatt laser, this scheme opens up possibilities for the convenient production of the relativistic hollow laser at high repetition and possible hollow plasma acceleration, which is important for a wide range of applications such as the generation of radiation sources with orbital angular momentum, fast ignition for inertial confinement fusion, and jet research in the astrophysical environment.

Label-free, fast, and single nanoparticle detection is demanded for the in situ monitoring of nano-pollutants in the environment, which have potential toxic effects on human health. We present the label-free imaging of single nanoparticles by using total internal reflection (TIR)-based leakage radiation microscopy. We illustrate the imaging of both single polystyrene (PS) and Au nanospheres with diameters as low as 100 and 30 nm, respectively. As both far-field imaging and simulated near-field electric field intensity distribution at the interface showed the same characteristics, i.e., the localized enhancement and interference of TIR evanescent waves, we confirmed the leakage radiation, transforming the near-field distribution to far-field for fast imaging. The localized enhancement of single PS and Au nanospheres were compared. We also illustrate the TIR-based leakage radiation imaging of single polystyrene nanospheres with different incident polarizations. The TIR-based leakage radiation microscopy method is a competitive alternative for the fast, in situ, label-free imaging of nano-pollutants.

The directional scattering in low-index dielectric nanoparticles is hard to detect, as the multipole resonances are weak. With surface plasmon polariton (SPP) induced multipole moments, we observed the directional SPP scattering by single polystyrene nanoparticles.

We presented a method to manipulate the surface plasmon propagation by using the total reflection of single hollow nanoparticle. We used plasmonic imaging to observe the manipulation by single hollow nanoparticle in different surrounding medium.

The synergistic combination of electric double-layer capacitance (EDLC) and pseudocapacitance is one of the most effective approaches to realize high-performance supercapacitor energy storage. Herein high specific energy and power supercapacitor is realized through the surface-dominant pseudocapacitive charge storage. To demonstrate that, a hybrid 1T-MoS2/Ti3C2Tx porous aerogel is rationally fabricated via bidirectional freeze-casting. The conductive Ti3C2Tx electrically connects the 1T-MoS2 nanosheets, which significantly improves the electron transfer and ion transport, leading to the surface-dominant (up to 86.9%) pseudocapacitive energy storage. As a result, the hybrid aerogel exhibits an outstanding capacitance of 392 F g−1 at 5 mV s−1, greatly higher than the conventional 1T-MoS2/Ti3C2Tx film and 1T-MoS2 film. Meanwhile, the Ti3C2Tx-connected 1T-MoS2 architecture achieves high capacitance retention (∼ 38%) at 1000 mV s−1, which is about 2.9 and 4.7 times higher than that of conventional 1T-MoS2/Ti3C2Tx film and 1T-MoS2 film, respectively. Moreover, the asymmetric supercapacitor delivers both high specific energy (45.3 Wh kg–1 at 924 W kg–1) and specific power (76.4 kW kg–1 at 18.9 Wh kg–1), among the best records of supercapacitors. This work opens new opportunities to develop next-generation high specific energy and power supercapacitors via synergistic effects of EDLC and pseudocapacitance.

In this erratum, the function λ S P P in the third page of Opt. Lett. 44, 5707 (2019)OPLEDP0146-959210.1364/OL.44.005707 has been corrected.

Due to their excellent physical and chemical properties, graphene sheets are widely used in industry, which makes detection important to guarantee their performance. Atomic force microscopy, scanning electron microscopy, and Raman spectroscopy are the most common detection methods, which is either time-consuming or easily destructive. In this work, we presented a fast and nondestructive method to detect single graphene sheets by using plasmonic imaging. Dual channel sampling plasmonic imaging combining the image processing algorithm is used to improve the deterioration from propagation length of surface plasmon polaritons and reconstruct the complete morphology of single graphene sheets. The fast and nondestructive detection method paves the way to applications of graphene, and can be extended to the detections of two-dimensional materials, single biological molecule, viruses, and nanomaterials.

Since the 1980s, alpine grasslands have been seriously degraded on the Tibetan Plateau. Grazing exclusion by fencing has been widely adopted to restore degraded grasslands. To clarify the effect of grazing exclusion on soil quality, we investigated soil properties and nutrients by comparing free-grazing (FG) and grazing exclusion (GE) grasslands in Tibet. Soil properties – including soil bulk density, pH, particle size distributions, and proportion of aggregates – showed no significant difference between FG and GE plots. Soil organic carbon, soil available nitrogen, and available phosphorus contents did not differ with grazing exclusion treatments in both the 0–15 and 15–30 cm layer. However, soil total nitrogen and total phosphorus contents were remarkably reduced due to grazing exclusion at 0–15 cm depth. Furthermore, growing season temperature and/or growing season precipitation had significant effects on almost all soil property and nutrient indicators. This study demonstrates that grazing exclusion had no impact on most soil properties and nutrients in Tibet. Additionally, the potential shift of climate conditions should be considered when recommending any policy designed for restoration of degraded soil in alpine grasslands in the future. Nevertheless, because the results of the present study come from a short-term (6–8 years) grazing exclusion, the assessments of the ecological effects of the grazing exclusion management strategy on soil quality of degraded alpine grasslands in Tibet still need long-term continued research.

Label-free single-nanoparticle detection is crucial for the fast detection of nanoparticles and viruses in environmental monitoring and biological sciences. In this Letter, benefiting from the leakage radiation that transforms the near-field surface plasmon polariton (SPP) distribution along the interface to the far field, we demonstrated the plasmonic imaging of single polystyrene nanoparticles with a particle size down to 39 nm. The imaging is composed of the localized enhancement and interference of SPPs. The localized enhancement is the result of the accumulation of charges around the nanoparticle, and it is connected to the size and refractive index of nanoparticles. The interference is induced by the coupling between the incident SPPs and the scattered SPPs, verified by extracting the interference fringe periodicity to be half of the SPP wavelength. Our study provides an in-depth physical understanding of plasmonic imaging of single nanoparticles, which paves the way for a fast identification of nanomaterials.

We study the physical mechanism of surface plasmon polariton in-plane scattering with single nanoparticle, which is vital to understand the electromagnetic interaction with nanoparticle. Also, the polarized bright spot is linear with the nanoparticle's size.

We present experimental studies on ion acceleration using an 800-nm circularly polarized laser pulse with a peak intensity of $6.9\ifmmode\times\else\texttimes\fi{}{10}^{19}\text{ }\text{ }\mathrm{W}/{\mathrm{cm}}^{2}$ interacting with an overdense plasma that is produced by a laser prepulse ionizing an initially ultrathin plastic foil. The proton spectra exhibit spectral peaks at energies up to 9 MeV with energy spreads of 30% and fluxes as high as $3\ifmmode\times\else\texttimes\fi{}{10}^{12}\text{ }\text{ }\mathrm{protons}/\mathrm{MeV}/\mathrm{sr}$. Two-dimensional particle-in-cell simulations reveal that collisionless shocks are efficiently launched by circularly polarized lasers in exploded plasmas, resulting in the acceleration of quasimonoenergetic proton beams. Furthermore, this scheme predicts the generation of quasimonoenergetic proton beams with peak energies of approximately 150 MeV using current laser technology, representing a significant step toward applications such as proton therapy.

An approach to image the single virus by using Surface Plasmon Polariton Scattering was presented, which is potential for application in the fast, in-situ virus detection in water environment. Polarized by Surface Plasmon Polaritons, the nanoparaticle emits Surface Plasmon Polariton Scattering and interferes with the incident Surface Plasmon Polaritons, which is easy to be detected. The imaging to Surface Plasmon Polariton excitation was implemented. Meanwhile, the imaging to single 39 nm polystyrene nanoparticle and single T4 phage virus by using the Surface Plasmon Polariton Scattering was obtained. Both the imaging and the accurate counting of single virus can be obtained by using this method.

Total Internal Reflection (TIR) microscopy combining fluorescent probe has been widely used in the bio-imaging. As the bleaching and quenching introduced by the fluorescent probe, people kept on looking for the label-free microscopic method. Studies on label-free imaging has been implemented by collecting the space scattering of evanescent wave excited by total internal reflection, and imaging to ~40 nm single gold nanoparticle and ~ 100 nm single virus has been achieved [1-2]. Here, we introduced a novel label-free TIR-based Interface Scattering approach, which images the single nanoparticle by using the interface scattering of evanescent wave. The evanescent wave excited by TIR-based illumination, then the nanoparticle polarizes and emits the scattering which includes both space and interface scattering (shown in Figure 1). The interface scattering interferes with the incident evanescent wave is collected for imaging. We presented the imaging of single 200nm and 100nm polystyrene nanoparticle (shown in Figure 2). This approach is potential for application in fast, in-situ, label-free nanoscale imaging.

Lower charge-to-mass ions are more difficult to be accelerated during the traditional single accelerating progress, because they are generally modulated by the weaker charge-separated electric field. In this paper, the cascaded target normal sheath acceleration (TNSA) mechanism is proposed to solve this issue in experiments, where the low charge-to-mass ions (C2+) generated from the first TNSA stage can be further tailored to a mono-energetic bunch by the peak of the sheath field in the additive TNSA stages. A simple numerical model is used to explain the experimental result and shows that the energetic spread of the ion beam can be further reduced from 27% to ∼1% by expanding the two-stage acceleration to triple-stage acceleration. Here, the sheath field works like a spectral knife that can control the peak energy and bandwidth of the spectra for the ions with any charge-to-mass ratio. More choices can be provided for many potential applications, such as ion therapy and nuclear physics.

We present a technique on focusing laser-driven proton beams in an array pattern by employing a copper mesh irradiated by a separate, intense laser pulse. Transient fields are generated on the mesh following the intense interaction. Under the combined effect of collisional scattering and electrical deflections from the mesh, a laser-driven proton beam is split into multiple focused beams with a high density of ∼4 × 109/cm2 after propagation through the charged-up mesh. The particle density within the focused beamlets is up to ∼11 times the initial density of the proton beam. Multiple beam focusing through this approach may open routes for proton beam conditioning, leading to opportunities for multi-beam applications, such as tomographic radiography and proton implantation.We present a technique on focusing laser-driven proton beams in an array pattern by employing a copper mesh irradiated by a separate, intense laser pulse. Transient fields are generated on the mesh following the intense interaction. Under the combined effect of collisional scattering and electrical deflections from the mesh, a laser-driven proton beam is split into multiple focused beams with a high density of ∼4 × 109/cm2 after propagation through the charged-up mesh. The particle density within the focused beamlets is up to ∼11 times the initial density of the proton beam. Multiple beam focusing through this approach may open routes for proton beam conditioning, leading to opportunities for multi-beam applications, such as tomographic radiography and proton implantation.

We measured terahertz (THz) radiation from GaAs (1 0 0) surface coated with rough Au film in the thickness ranging from 5 to 21 nm under the incident angle from 0° to 50°. Anomalous THz emission was observed with inhomogeneous crack structures at normal incidence, which originates dominantly from the lateral photo-Dember current. Meanwhile, enhanced THz radiation from Au/GaAs was investigated with the variation of the Au morphology, which confirmed that localized surface plasmons play an important role in the THz radiation. The results indicate the prospect of harnessing surface plasmons for efficient THz emission with controllable morphology of Au on semiconductors.

Terahertz (THz) emission from octadecanthiol (ODT) passivated (1 0 0) surface of the semi-insulating GaAs was measured, and compared with those from the native oxidized and the fresh surfaces. It was shown that the self-assembled ODT monolayer can stabilize the GaAs (1 0 0) surface, and maintain a THz surface emission 1.4 times as efficient as the native oxidized surface under equal conditions. Surface passivation can reduce the built-in electric field in the depletion region of the GaAs (1 0 0), resulting in the suppression of the THz radiation to a different extent. Oxidation of GaAs surface reduces the THz amplitude mainly in the low-frequency region. These results indicate that GaAs can be made a more effective THz source by choosing molecular passivation technique. Conversely, the THz emission features such as polarity, amplitude, and phase from molecule-passivated surfaces may be used to characterize the attached molecules.

Both the localized resonance and excitation of spoof surface plasmon polaritons are observed in the terahertz transmission spectra of periodic subwavelength hole arrays. Analyzing with the coupled oscillator model, we find that the terahertz transmission is actually facilitated by three successive processes: the incident terahertz field first initiates the localized oscillation around each hole and then the spoof surface plasmon polaritons are excited by the localized resonance and finally the two resonances couple and contribute to the transmission. Tailoring the localized resonance by hole size, the coupling strength between spoof surface plasmon polaritons and localized resonances is quantitatively extracted. The hole size dependent transmittance and the coupling mechanism are further confirmed by fitting the measured spectra to a modified multi-order Fano model.

A review of localized plasmonic properties of 2-D terahertz (THz) metallic geometries is presented. The high electric conductivity of metals in the THz regime enables fascinating plasmonic behaviors observed in metallic structures of subwavelength dimensions. Strong electric field enhancement was demonstrated in arrays of various subwavelength metallic particles including patches, rings, and ring-patch coaxials. We also show that periodic arrays of integrated coaxials comprised of patches and subwavelength holes not only resulted in a factor-of-eight increase in normalized transmittance compared to that of the hole-only counterpart, but also tailored polarization dependent transmission discrepancy encountered in arrays of rectangular holes. The localized plasmonic properties and the resulted electric field enhancement will find fascinating applications in THz sensing, spectroscopy, and integrated components.

A double beam image (DBI) technique is coupled in the two-stage accelerating mechanism to simultaneously improve the spectra and maximum energy of the proton beam. A proton beam with a narrow-spectrum center at 5.4 MeV and a long tail up to 14.4 MeV is generated in the experiment. Experimental and simulation results show that spatial collineation, time synchronization, and real-time monitoring are needed for optimum two-stage proton acceleration and are realized by the DBI technique to a certain extent in our experiment. This DBI technique can be used to achieve optimum two-stage acceleration in a feasible manner and will allow precise manipulation of multistage acceleration to improve the energy and spectra of particle beams.

We study the role of non-resonant effect in enhanced transmission of terahertz pulses through periodic array of subwavelength holes. The measured terahertz transmission spectra exhibit a characteristic evolution with various hole widths. The peak transmission approaches a maximum value at a critical hole width, while monotonic linewidth broadening and blueshift are observed when the hole width increases. The physical mechanism responsible for such transmission properties is closely associated with the coupling between discrete resonant excitation of surface plasmons and continuum non-resonant transmission through the holes.

Firstly employing coupled oscillator model to quantitatively analyze the Terahertz enhanced transmission through sub-wavelength hole arrays, we clarify the surface plasmons resonance is excited by the localized resonance via coupling instead of the external E-field.

We present an experimental demonstration of surface plasmon enhanced terahertz spectroscopic identification of methyl alcohol isotopes by use of metallic array of subwavelength holes. Due to isotopic hydrogen/deuterium substitution, the refractive indices of methyl alcohol and isotopes vary from each other in the terahertz regime. This leads to a modification in the wave vector and consequently the resonance condition of surface plasmons excited at the metal–dielectric interface. A distinct resonance shift and an amplitude modification are observed, giving high characterization sensitivity and thereby demonstrating that such plasmonic array has potential in developing new techniques in isotope distinguishing.

Surface-enhanced electromagnetic response in the resonant regions of split-ring resonators offers a sensitive way to probe the surface dipoles formed by alkanethiol molecules with a terahertz wave by a differential transmission (DT) interrogation method. The DT signal mainly comes from the interaction between alkanethiols and metamaterials by electron transfer and/or the variation of the dielectric constant. The Lorentz model is used to demonstrate the principle of DT interrogation theoretically, which suggests the variation of both frequency and damping of resonance can be captured cooperatively. This method has been employed to experimentally demonstrate the sensing feasibility for the chain length dependence of the alkanethiol molecules. Numerical simulations confirm that the enhancement is large at the gap and corner regions of this kind of metamaterials.