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The development of lithium-niobate-on-insulator (LNOI) technology has sparked the advancement of numerous on-chip photonic devices for generating and manipulating light. However, the optical absorption of thin-film LNOI is very weak, especially in the near-infrared field, due to their extremely thin absorption layer and intrinsic band structure characteristics. Here, we propose a comprehensive framework to tackle these obstacles by means of ion implantation of Ag ions, which facilitates the encapsulation of plasmonic silver (Ag) nanoparticles within LNOI thin films. Through the incorporation of Ag nanoparticles, we have observed a tailored profile of optical nonlinear absorptions in LNOI thin films, transitioning from reverse saturable absorption to saturable absorption as well as optical-induced absorption to photobleaching behaviors. Moreover, the plasmonic effect elicited by the embedded Ag nanoparticles amplifies the third-order nonlinear coefficient by an order of magnitude. This work opens an avenue toward the development of high-performance on-chip photonic devices harnessing third-order nonlinearities of LNOI. [ABSTRACT FROM AUTHOR]

High-entropy oxide (HEO) nanoparticles have been regarded as a promising catalytic material system for oxygen evolution reaction in recent years. However, their traditional physical and chemical synthesis remains challenges due to the limitation of fabricating controllable small size HEO nanoparticles. Herein, a general and novel method of low-energy-recoil ion implantation and subsequent annealing is successfully developed to synthesize high-entropy oxide nanoparticles catalysts. By controlling the fluence of irradiation Ar+ ions, the size and the load of HEO nanoparticles can be accurately controlled. The obtained (FeCoNiCrAl)O HEO nanoparticles exhibit an overpotential of 295 mV at 10 mA cm−2, a small Tafel slope of 39 mV dec−1 and good stability in 1 M KOH, which is much better than the properties of binary and medium entropy oxide counterparts prepared by the same method, showing the good application prospect of low-energy-recoil ion implantation in the preparation of complicated multi-element-metal oxide nanoparticles. [ABSTRACT FROM AUTHOR]

The Faraday rotation originates from the mechanism by which the time‐reversal symmetry in the material is broken by the external magnetic field. It is the basis for the development of some magneto‐optical devices, such as optical isolators. In integrated optics and telecommunications, nonreciprocal photonic devices with high transmittance and strong Faraday rotation are desired for low‐cost, compact optical systems. Localized surface plasmon resonance (LSPR) from the metallic nanoparticles in dielectrics allows the light localization in subwavelength scales, boosting the interaction between nanoparticles and materials, which results in a number of plasmon‐enhanced effects. Herein, the strong Faraday rotation in BK7 glass by embedded metallic nanoparticles through LSPR is reported. It is elucidated that the mechanism of Faraday rotation is the near‐field enhancement of spin–photon coupling effect in the presence of an external magnetic field. The Verdet constant of the thin‐layer BK7 glass with embedded Au nanoparticles is determined as high as 5059.7 rad T−1 m−1 at 532 nm, exhibiting excellent magneto‐optical features. This work opens a new avenue to develop the subwavelength magneto‐optical devices with embedded metallic nanoparticles. [ABSTRACT FROM AUTHOR]

Ultrafast lasers play important roles for scientific research and industrial applications. Saturable absorbers serve as crucial components for ultrafast laser generation. For decades, securing saturable absorbers with superior performance is one of the focuses in the field of advanced laser technology. In this work, the authors fabricate a new saturable absorption mirror (SAM) based on BK7 glass wafer, which is with a buried thin‐layer of silver (Ag) nanoparticles (NPs). The embedded Ag NPs‐based SAM (Ag‐NPs‐SAM) possesses excellent saturable absorption features due to the localized surface plasmon resonance (LSPR) effect of Ag NPs, and outstanding environmental stability owing to the protection of insulating dielectrics. In addition, benefiting from the ultrafast recovery time of Ag NPs, a continuous‐wave mode‐locking operation with the embedded Ag‐NPs‐SAM at 1037 nm is achieved in a Yb:KGW solid‐state laser system, obtaining pulses of a duration as short as 324 fs. The authors work offers a new strategy toward broadband response and high‐stability saturable absorbers for developing advanced ultrafast lasers. [ABSTRACT FROM AUTHOR]

Developing efficient methods for boosting light–matter interactions is critical to improve the functionalities of two-dimensional (2D) transition metal dichalcogenides toward next-generation optoelectronic devices. Here, we demonstrate that the light–matter interactions in tungsten disulfide (WS2) monolayer can be significantly enhanced by introducing an air-stable functional substrate (fused silica with embedded plasmonic Ag nanoparticles). Distinctive from conventional strategies, the Ag nanoparticles are embedded under the surface of fused silica via ion implantation, forming a functional substrate for WS2 monolayer with remarkably environmental stability. A tenfold photoluminescence enhancement in WS2 monolayer has been achieved due to the plasmonic effect of Ag nanoparticles. This work offers a strategy to fabricate the plasmon-2D hybrid system at low cost and large scale and paves the way for their applications in optoelectronics and photonics. [ABSTRACT FROM AUTHOR]

Brilliant plasmonic colors with long‐standing stability are generated via laser direct writing. This plasmonic coloring system is made of silver nanoparticles (Ag NPs) layer embedded in the quartz glass formed by ion implantation. The laser‐induced plasmonic heating merges the small Ag NPs into larger ones, which modifies the plasmon resonances. The plasmon resonances can be further tuned via changing the irradiation time and power, which shows scattering colors ranging from red to green and cyan. By scanning the laser across the Ag NPs layer, sophisticated plasmonic patterns and images with high resolution (≈105 DPI) can be obtained and preserved over long time (several months). This plasmonic coloring system via laser printing is facile, cost‐effective, accurate, and highly stable with rich hue, compared to other plasmonic color systems, which bears significant potentials for industrial applications such as optics, displays, decorations, data storage, and anti‐counterfeiting. [ABSTRACT FROM AUTHOR]

Monolithic waveguide laser devices are required to achieve on-chip lasing. In this work, a new design of a monolithic device with embedded Ag nanoparticles (NPs) plus the Nd:YAG ridge waveguide has been proposed and implemented. By using Ag+ ion implantation, the embedded Ag NPs are synthesized on the near-surface region of the Nd:YAG crystal, resulting in the significant enhancement of the optical nonlinearity of Nd:YAG and offering saturable absorption properties of the crystal at a wide wavelength band. The subsequent processing of the O5+ ion implantation and diamond saw dicing of crystal finally leads to the fabrication of monolithic waveguide with embedded Ag NPs. Under an optical pump, the Q-switched mode-locked waveguide lasers operating at 1 μm is realized with the pulse duration of 29.5 ps and fundamental repetition rate of 10.53 GHz, owing to the modulation of Ag NPs through evanescent field interaction with waveguide modes. This work introduces a new approach in the application of monolithic ultrafast laser devices by using embedded metallic NPs. [ABSTRACT FROM AUTHOR]

In this work, V ions were doped into ZnO nanorod arrays via an advanced ion implantation method for photoelectrochemical water splitting under visible light. It was indicated that the V dopants were incorporated into ZnO lattice as V 4+ and V 5+ ions. V ion doping expanded the optical absorption of ZnO nanorod arrays into visible light region and led to considerable photoelectrochemical performance under visible light illumination ( λ > 420 nm). The photocurrent density of V ions doped ZnO nanorod arrays could achieve 10.5 μA/cm 2 at 0.8 V (vs. Ag/AgCl), which was about 4 times higher than that of the pure ZnO nanorod arrays. The enhancement in photoelectrochemical performances for V ions doped ZnO nanorod arrays should be attributed to the improved visible light absorption ability and the increased charge carrier density induced by V ion doping. [ABSTRACT FROM AUTHOR]

Embedded silver nanoparticles were produced in KTP single crystal by 200 keV Ag + ion implantation at fluence of 5 × 10 16 ions/cm 2 . The shape, size and spatial distribution of the formed silver nanoparticles were revealed by transmission electronic microscope (TEM) images. The embedded sphere silver nanoparticles with average diameters of 9.9 nm were along the projected range of Ag + ions, located at the depth between 35 nm and 80 nm from the surface. Both the measured and calculated absorption spectra of silver nanoparticles dispersed in KTP crystal indicate that the surface plasmon resonance (SPR) absorption peak was at ∼459 nm. [ABSTRACT FROM AUTHOR]

Highlights: [•] Fabrication of TiO2 films by ion implantation and annealing strongly depends on ion energy. [•] Best photocatalytic activity is achieved in the TiO2 nanofilm annealed at 1000°C. [•] Phase transformation of TiO2 appears under annealing temperature of 900°C. [ABSTRACT FROM AUTHOR]

Triboelectric polymers have attracted tremendous attention due to the fast development of triboelectric nanogenerator (TENG). However, the detailed factors determining the polarity and the intensity of the electrification in polymers are still not fully revealed. Here, we demonstrated that N-containing polar groups and unsaturated bonds can break the spatial structural symmetry of the polytetrafluoroethylene (PTFE), improve the polarity and electronegativity of groups, turn them into polar polymers, intensify the electron cloud overlap to enhance the electron-withdrawing (EW) capability, thereby accurately regulate their electrification properties. In order to improve the triboelectric performance, a different modification strategy based on ion implantation technique is reported for generating these specific bonds to achieve ultrahigh negative triboelectric polymers. The modified fluorinated polymers exhibit ultrahigh negative triboelectric polarity and their surface charge density have 4~8 times enhancements comparing with original samples. Meanwhile, stronger polarity doubles the dielectric constant and further enhances the energy storage density of the material. The physical study in this work elaborates the fundamental mechanism by which molecular structures regulate macroscopic electrical properties, which provides a guidance for manufacturing advanced triboelectric polymers through the micro-regulation of polarity. There is a newly modification strategy based on ion implantation technique for regulating the polar bonds and unsaturated bonds of the polymer to prepare super negative triboelectric polymers. Their transferred densities increase 8 times than original samples. [Display omitted] • A different modification strategy based on N ion implantation technique is firstly reported. • The modified PTFE and FEP films have 4–8 times enhancements (125 μC m-2 and 230 μC m-2) on surface charge density. • Strong N-containing polar groups break the spatial structural symmetry of the PTFEs and enhance the electron-withdrawing capability. [ABSTRACT FROM AUTHOR]

Abstract: Cu nanoclusters embedded in silica glass were formed by ion implantation with different doses. Optical absorption spectra of the implanted samples showed peaks around 570nm, attributed to the surface plasmon resonance (SPR) absorption of Cu nanoclusters. Optical absorption increased with the increasing of doses, but decreased for dose higher than 1.5×1017 ions/cm2 due to the surface-sputtering effect. The positions of resonance peaks were slowly red-shifted with increasing annealing temperature in oxidizing atmosphere. The red-shift is mainly attributed to the interaction of Cu nanoclusters with diffused oxygen from the oxidizing atmosphere. With increasing annealing temperature, a new absorption at 300nm was observed while the absorption belonging to SPR disappeared. The formation of Cu nanoclusters was also observed by transmission electron microscopy measurement. [Copyright &y& Elsevier]

Saturable absorbers are key elements for generation of ultrafast laser pulses. The commercially available semiconductor saturable absorber mirrors are wavelength sensitive and with complex fabrication process and high cost. Fused silica is one of the basic materials for various optical applications. Plasmonic nanoparticles can be used to efficiently modulate the optical properties of dielectric materials owing to the enhanced field effects based on localized surface plasmonic resonance. Ion implantation is a direct technique to synthesize plasmonic nanoparticles inside dielectric materials, which can simultaneously tailor the optical nonlinearity of substrates significantly. In this work, Ag ion implantation into fused silica with tunable interparticle spacing is used to generate broadband optical nonlinearities and to endow silica with ultrafast saturable absorption property. This ion implantation forms a 2D‐like Ag nanoparticle monolayer buried inside fused silica wafer. The fused silica with embedded 2D‐like Ag nanoparticle monolayer is further applied as a new saturable absorber to generate ultrafast laser pulses with pulse duration of 27 ps and repetition rate of 6.5 GHz through the passive mode‐locking process. This work opens up a new route to develop low‐cost, highly stable saturable absorbers, and offers the possibility to build novel silica‐based photonic systems through nanoparticle spacing manipulation. [ABSTRACT FROM AUTHOR]

Oxygen vacancy can greatly affect the performance of metal oxide to hydrogen isotope permeation resistance. In this work, we report a new strategy to improve the permeation resistance by oxygen ion implantation. A (TiVAlCrZr)O multi-component metal oxide film was prepared as a tritium permeation barrier on a 316 L substrate by RF magnetron sputtering deposition, and then implanted by oxygen ions to fill the oxygen vacancies inside. The grazing incidence X-rays (GIXRD) analysis showed that the pristine and the oxygen-implanted coatings were in an amorphous phase. The deuterium permeation resistance of the four coatings was tested by a gas-driven device. The result showed that the pristine coating had a permeation reduction factor (PRF) of 5,610 at 500 °C, while there was a 13.6 times of increase in PRF with an oxygen concentration of 11.4 at.% with the best-reported value of 76,500, and more oxygen ions implanted, the better the deuterium permeation resistance of the coating. The GIXRD showed that after the test the pristine coating remained amorphous, while some crystals were formed in the oxygen-implanted coating with an oxygen concentration of 11.4 at.%. Oxygen ion implantation enhanced the deuterium permeation resistance by filling the oxygen vacancies and forming of more stable state of amorphous multi-component metal oxide, which is expected to be a new type of deuterium permeation barrier. [ABSTRACT FROM AUTHOR]

Abstract: The evolution of nanoparticles in sequentially ion-implanted Ag and Ag/Cu into silica glasses has been studied. The doses for implantation (×1016 ions/cm2) were 5Ag, 5Ag/5Cu and 5Ag/15Cu. Ag nanoclusters have been formed in the implanted 5Ag specimen. In the implanted 5Ag/5Cu specimen, some formed nanoclusters have brighter center features. With an increase of Cu ions dose, the nanoclusters with brighter center features become prevalent. The microstructural properties of the nanoparticles are characterized by transmission electron microscopy. Scanning transmission electron microscope high-angle annular dark field and high-resolution transmission electron microscopy are also utilized to study the formed nanoparticles. The results show that nanovoids have been induced into metal nanoparticles during the ion implanting process, not the core-shell nanoparticles as other workers believed. The nanovoids can be the aggregation of vacancies induced by irradiation. [Copyright &y& Elsevier]

Hematite is a prospective semiconductor in photoelectrochemical (PEC) water oxidation field due to its suitable bandgap for the solar spectrum absorption. Nevertheless, the low transfer and separation efficiency of the charge carriers are restricted by its diffusion length of hole which is 2–4 nm and further reduce the PEC performance. Here, we report an innovative method, by introducing nanocavities into the α-Fe 2 O 3 nanorod arrays photoanodes through helium ions implantation, to improve the charge carriers' transfer and separation efficiency and further to enhance water oxidation performance. The result indicates that, the photocurrent density of nanocavities embedded α-Fe 2 O 3 photoanode (S2-A sample) reaches 1.270 mA/cm2 at 1.6 V vs. RHE which is 1-fold higher than that of the pristine α-Fe 2 O 3 (0.688 mA/cm2) and the photocurrent density of S2-A sample reaches 0.652 mA/cm2 at 1.23 V vs. RHE. In this work, the ion implantation combined with post annealing method is found to be a valid method to improve the photoelectrochemical performance, and it also can be further used to modify the other semiconductor photoelectrodes materials. • The photoelectrochemical performance of α-Fe 2 O 3 photoanode was enhanced through controlled He+ ion implantation. • The size and density of nanocavities in the α-Fe 2 O 3 nanorods can be tailored by controlling the ion fluences. • Nanocavities can increase the separation efficiency of electron-hole pairs. [ABSTRACT FROM AUTHOR]

Abstract: Ag-nanoparticles were embedded in the 56GeS2–24Ga2S3–20KBr chalcohalide glasses with varied doses by ion implantation. Ag-nanoparticles were observed in the AFM images of all implanted samples. The third-order optical nonlinearity of Ag-implanted chalcohalide glasses was investigated by the femtosecond Z-scan measurements. The results indicated an enhancement of third-order optical nonlinearity due to the formation of Ag-nanoparticles in glasses. The relation between implanting dose and third-order optical nonlinearity was strongly related to the intrinsic local field and interaction of Ag-nanoparticles. [Copyright &y& Elsevier]

• PL and Raman spectra of Pr:CaF 2 crystal are first enhanced by embedded Ag nanoparticles. • This PL enhancement is experimentally analyzed to the local field enhancement instead of energy transfer. • Different local field enhancements induced by excitation coefficient and radiative decay rate are analyzed, respectively. Photoluminescence (PL) enhancement of rare earth ions is in high demand due to their crucial applications in optoelectronics devices and biomedical frequency up-convertors for endoscopy, which could be realized by a plasmonic field enhancement effect of metallic nanoparticles (NPs). In this work, both the PL emission and Raman scattering enhancement of Pr3+ ions in CaF 2 crystal host have been observed for the first time by embedding silver NPs. By Ag+ ion implantation, Ag NPs (around 5 nm) have been encapsulated into the Pr:CaF 2 matrix. Analysis of the difference between linear optical absorption and PL excitation spectra within the plasmon band, the mechanism of observed PL enhancement has been attributed to the local field enhancement induced by the plasmonic NPs. The classical energy transfer process nanoparticle-emitter was not present. The detailed analysis of the PL enhancement induced by unannealed and annealed Ag NPs is compared under the measurement of PL decay, showing the dominant mechanism of the increased absorption and radiative decay rate, respectively. This work shows an efficient method to enhance PL emission of rare earth ions in the crystal based on the embedded metallic NPs, which could be used to optimize the photonic sensors and light emitting devices. [ABSTRACT FROM AUTHOR]

Ion implantation is a facile surface modification technology for greatly tailoring the surface electron structure of materials, which is very important for catalytic activity. Here we report a new universal synthesis of stable, large-scale N-doped carbon fiber cloth embedded with non-noble metal nanoparticles (CN@(Ni, Fe and Co)) by ion implantation for largely enhanced hydrogen evolution reaction (HER) activity under acidic (0.5 M H 2 SO 4), neutral (0.5 M phosphate buffer, PH = 7) and basic solution (1M KOH). From the polarization curves, the overpotentials of current density for CN@Ni at 10 mA/cm2 decrease obviously from 710, 838 and 717 mV to 381, 589 and 532 mV in acidic, neutral and basic solution, respectively. Density functional theory (DFT) calculations also demonstrate that the Gibbs free energy (ΔG H∗) for H∗ adsorption of CN@Ni is much closer to the optimal value of ΔG H∗ = 0.15 eV compared with 1.84 eV of C and 0.86 eV of CN. The method is general and we demonstrate it using Fe+ and Co+ ions implantation into carbon fiber cloth to fabricate metal nanoparticles embedded carbon fiber cloth. Furthermore, this controlled technique is promising for industrial production of noble-metal-free HER electrocatalysts with large scale, low cost and high efficiency. • Metal nanoparticles embedded N-doped carbon fiber cloth was fabricated by metal ions implantation. • Greatly improved hydrogen evolution reaction performance in all pH range. • A general method for large-scale fabrication. [ABSTRACT FROM AUTHOR]