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This study investigates the translational and rovibrational energy of vacuum-ultraviolet (VUV) photodesorbed CO molecules from a CO polycrystalline ice (15 K) at ∼8 eV. The electronic excitation was produced by a pulsed VUV laser, and the photodesorption of CO molecules in their ground and first vibrational states was observed using resonance enhanced multiphoton ionization. Time-of-flight and rotationally resolved spectra were measured, and the kinetic and internal energy distribution were obtained. Vibrationally cold CO molecules were observed, with little energy in rotation and translation (≤300 meV). Ab Initio Molecular Dynamics (AIMD) simulations focusing on the description of the vibrational energy redistribution within an aggregate of 50 CO molecules were performed. The measured energy distributions are in very good agreement with those predicted by AIMD simulations. The rotational energy was found to slightly increase with translational energy, a trend also predicted by theory. This confirms the validity of the indirect desorption mechanism triggered by the excitation of CO in a high vibrational state. [ABSTRACT FROM AUTHOR]

Ferroelectric properties of hafnium-based thin films have gained significant interest, yet the fundamental mechanisms responsible for the emergence of the ferroelectric phase continue to be inadequately investigated. In contrast with polycrystalline films fabricated by atomic layer deposition or sputter methods, which possess uncertainty in polarization orientation, epitaxial ferroelectric HfO2-based materials are less investigated, especially for factors such as electric field and oxygen vacancy, which are proposed and examined for their potential impacts on phase stability. In this study, Y-doped hafnium oxide (HYO) ferroelectric epitaxial films were fabricated using pulsed laser deposition, with variations in oxygen pressure during the deposition process. Structural and electrical analyses of HYO epitaxial ferroelectric films prepared under differing oxygen pressures revealed a correlation between the ferroelectric properties of the films and the oxygen content. An optimal selection of oxygen pressure was found to be conducive to the formation of HYO epitaxial ferroelectric films, presenting a promising avenue for future ferroelectric memory applications. [ABSTRACT FROM AUTHOR]

Ferroelectric properties of hafnium-based thin films have gained significant interest, yet the fundamental mechanisms responsible for the emergence of the ferroelectric phase continue to be inadequately investigated. In contrast with polycrystalline films fabricated by atomic layer deposition or sputter methods, which possess uncertainty in polarization orientation, epitaxial ferroelectric HfO2-based materials are less investigated, especially for factors such as electric field and oxygen vacancy, which are proposed and examined for their potential impacts on phase stability. In this study, Y-doped hafnium oxide (HYO) ferroelectric epitaxial films were fabricated using pulsed laser deposition, with variations in oxygen pressure during the deposition process. Structural and electrical analyses of HYO epitaxial ferroelectric films prepared under differing oxygen pressures revealed a correlation between the ferroelectric properties of the films and the oxygen content. An optimal selection of oxygen pressure was found to be conducive to the formation of HYO epitaxial ferroelectric films, presenting a promising avenue for future ferroelectric memory applications. [ABSTRACT FROM AUTHOR]

Plasmonic catalysis triggers the dissociation of H 2 or adsorbed O 2 (sluggish processes) under continuous wave excitation via plasmon decay. This is coupled to interband or intraband excitation of d-band or sp-band, respectively, to levels above fermi level of metals. Here, we have studied the plasmonic and photocatalytic behavior in an environment friendly medium with AM 1.5 G sunlight of CuO/ Cu 2 O thin films fabricated by pulsed laser deposition technique in vacuum with varying thickness. We have achieved ∼ 0.59 kmol h − 1 g − 1 H 2 production in the CuO/ Cu 2 O film with a thickness of ∼ 27 nm. The role of plasmons with metal–dielectric and semiconductor–semiconductor interfaces is conducted through both experimental and theoretical approaches. The results suggest that the impact of plasmonic catalysis/synthesis is subject to the dimension, composition, and band alignment of two interface materials. [ABSTRACT FROM AUTHOR]

This article reports the superparamagnetic behavior of metal-free nitrogen-doped graphene quantum dots (N-GQDs). The pulsed laser ablation (PLA) method was utilized to synthesize N-GQDs with an average diameter of 3.45 nm and a high doping level (N/C) of 1.4. Magnetic properties of as-synthesized N-GQDs were explored by performing magnetization vs magnetic field (M–H) and magnetization vs temperature (M–T) measurements. M–H plots measured in a temperature range of 2–300 K revealed the superparamagnetic behavior of N-GQDs. The value of saturation magnetization was found to be directly correlated to nitrogen concentration and a saturation magnetization up to 28.7 emu/g was obtained at room temperature (300 K). M–T measurements with zero-field-cooled (ZFC) and field-cooled (FC) conditions were employed to study anisotropy energy barriers and blocking temperature. A variation in the blocking temperature (TB) from 288 to 61 K was observed when the external magnetic field (H) was changed from 0.1 to 0.6 T. The origin of superparamagnetism was attributed to the presence of graphitic nitrogen bonding configuration and defect states. The observed superparamagnetic properties along with the optical properties of N-GQDs create an opportunity for developing materials for biomedical applications and data recording devices. [ABSTRACT FROM AUTHOR]

Most semiconductors exhibit a saturation of free carriers when heavily doped with extrinsic dopants. This carrier saturation or "doping limit" is known to be related to the formation of native compensating defects, which, in turn, depends on the energy positions of their conduction band minimum and valence band maximum. Here, we carried out a systematic study on the n-type doping limit of GaAs via ion implantation and showed that this doping limitation can be alleviated by the transient process of pulsed laser melting (PLM). For n-type doping, both group VI (S) and amphoteric group IV (Si and Ge) dopants were implanted in GaAs. For comparison, p-type doping was also studied using Zn as the acceptor. Implanted dopants were activated by the PLM method, and the results are compared to rapid thermal annealing (RTA). Our results reveal that for all n-type dopants, while implantation followed by the RTA results in a similar saturation electron concentration of 2–3 × 1018 cm−3, the transient PLM process is capable of trapping high concentration of dopants in the substitutional site, giving rise to a carrier concentration of >1019 cm−3, exceeding the doping limit of GaAs. However, due to scatterings from point defects generated during PLM, the mobility of n-type GaAs after PLM is low (∼80–260 cm2/V s). Subsequent RTA after PLM (PLM + RTA) is able to remove these point defects and recover the mobility to ∼1000–2000 cm2/V s. The carrier concentrations of these PLM + RTA samples are reduced but are still a factor of 3 higher than RTA only GaAs. This can be understood as the dopants are already incorporated in the substitutional site after PLM; they are less likely to be "deactivated" by subsequent RTA. This work is significant to the understanding of doping mechanisms in semiconductors and provides a means for device applications, which require materials with ultra-high doping. [ABSTRACT FROM AUTHOR]

The increasing demand for functional nanodevices in sustainable energy applications necessitates the development of innovative approaches. In this study, we present the fabrication and characterization of three-dimensional (3D) structures coated with titanium dioxide (TiO 2) nanorods (NRs). These novel devices are created through the integration of four distinct techniques, multi-photon lithography, post-thermal treatment, pulsed laser deposition, and an aqueous chemical growth, enabling their unique properties and functionalities in photocatalysis. The photocatalytic performance of the 3D devices is evaluated through the degradation of organic pollutants, such as methylene blue and stearic acid, showcasing their efficiency in reducing pollutant concentrations. The devices demonstrate a remarkable decomposition coefficient (k = 0.059 min − 1 ), highlighting their enhanced photocatalytic efficiency. Additionally, we propose a rapid fabrication technique using 3D holographic printing to create large-area TiO 2 -coated micro-structured photocatalytic devices at the mesoscale regime. This approach increases the active surface area, further enhancing the devices' photocatalytic capabilities. By combining additive micro-manufacturing, TiO 2 NR coating, and holographic printing, our work introduces a promising avenue for the development of advanced nanodevices with superior photocatalytic performance in sustainable energy applications. [ABSTRACT FROM AUTHOR]

We have effectively shown a technique for significantly altering the nonlinear saturable absorption (SA) properties of nanocomposite films (NCFs) based on poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT:PSS) and molybdenum disulfide (MoS2) by regulating MoS2 concentration and input pulse energy of the laser. The NCFs are made using the straightforward drop-cast process on a glass substrate with varying quantities of MoS2. The produced NCFs' refractive index (n) and extinction coefficient (k) values are determined using the Kramers–Kronig equations. Nonlinear studies show that the optical nonlinearity of pure PEDOT:PSS changes when mixed with MoS2. The Pauli blocking has been observed in MoS2/PEDOT:PSS NCFs. This leads to enhanced SA in NCF. The open-aperture Z-scan approach is used for the nonlinear optical research, and a nanosecond pulsed laser with a wavelength of 532 nm is used for the excitation. The findings obtained show the NCFs' strong SA qualities. [ABSTRACT FROM AUTHOR]

Forward stimulated Raman scattering and backward stimulated Raman scattering (BSRS) are measured when an intense 532 nm nanosecond pulsed laser is focused into water and heavy water. The investigation reveals a significant observation: the formation of the ice VII structure exclusively occurs in the backward direction when optical breakdown takes place, provided that the input energy falls below 90 mJ for liquid water or 75 mJ for heavy water. This phase transition is attributed to secondary shock compression, which comes from energy transfer and compression between the BSRS in plasmas with the pump laser. The optical breakdown experiment under pre-pressure reveals that the shock compression in the back direction is approximately 2.3 times that of the forward direction. This research is useful for shock compression and dynamics in plasmas. [ABSTRACT FROM AUTHOR]

The effect of subnanosecond laser pulses on the structure and electronic subsystem of extended defects in cubic semiconductors was studied using cadmium telluride (CdTe) as an example. A CdTe epitaxial film containing threading dislocations was exposed to pulsed laser emission at helium temperatures. This exposure led to a local rearrangement of dislocation, while the properties of the crystal lattice remained undisturbed. The rearrangement was visualized in situ via an observation of the single luminescent centers associated with the partial dislocation cores. The rearrangements in the center of the laser spot, as well as those far from this location, were detected, thus revealing the laser treatment's non-thermal, relatively long-range influence. We associated the corresponding mechanism with Peierls's gliding of dislocation under the impact of laser-induced hypersonic surface waves. The results we obtained are of interest in the development of all-optical methods for the local laser processing of extended defects in CdTe and subsequent expansion those methods to other A 2 B 6 cubic semiconductors. [ABSTRACT FROM AUTHOR]

The additive manufacturing is a free-form metal deposition process, which allows generating a prototype or small series of near net-shape structures. Despite numerous advantages, one of the most critical issues of the technique is that produced pieces have a deleterious surface quality which requires post machining. Besides conventional post processes such as turning, milling, or photo-chemical etching, laser processes are increasingly being used for surface finishing of metals. In this study, a hybrid laser polishing technique consisting of nanosecond pulsed laser material removal and continuous wave (CW) laser polishing was utilized to polish the laser directed energy deposition (LDED) Ti-6Al-4 V samples. To account for this, the effect of hybrid laser polishing on the surface modification of LDED Ti-6Al-4 V alloy has been investigated. The surface morphology, microstructure evolution, and mechanical properties of the as-fabricated, the pulsed laser material removal processed, and the hybrid laser polishing processed samples were investigated. The results revealed that hybrid laser polishing not only eliminates the unmelted particles, oxides, and defects of as-fabricated Ti-6Al-4 V but also reconstructs the surface morphology, which improved the surface roughness by 98.32%. After hybrid laser polishing, the average thickness of the remelted layer has increased to 85 μm, while the acicular martensite α´ grows epitaxially from the substrate across the layer bands. Additionally, due to the formation of α′ martensite, the microhardness is about 21.02% higher than LDED Ti-6Al-4 V sample. The wear rate is decreased from 1.36 × 10−3 to 0.86 × 10−3 mm3/N·m, which was reduced by 38.23% compared to the as-fabricated. [ABSTRACT FROM AUTHOR]

Addressing the challenge of breaking rocks deep within the earth requires innovative solutions, and the pulsed laser technology has emerged as a promising noncontact alternative for rock breaking. We developed an automated experimental platform with robotic arms and a rock mechanics testing device to quantitatively study the impact of laser technology on rock breaking. Our investigation delved into the damage caused to rocks by different types of lasers, focusing on understanding their underlying damage mechanisms. Pulsed lasers, excluding thermal effects, reduced the red sandstone strength by 68.07%, with a decrease in peak tensile force by 30-33 N per 1000 pulses. Furthermore, we conducted detailed quantitative analyses to understand how laser power (P), irradiation duration, and output energy affeted rock damage. Increasing laser power or irradiation duration enhanced rock damage since this increased the laser output energy. For every 100.00 W power increase, the peak force decreased by 51.00-88.00 N, and for every 1000.00 ms duration increase, the peak force decreased by 34.00-42.00 N. Maintaining constant output energy while changing the laser power revealed a quadratic nonlinearity in peak force, aiding in determining optimal laser parameters. This study highlights the potential of laser technology for effective rock fracturing during deep earth exploration. The established experimental platform improves the accuracy and reliability of laser-induced rock breaking, offering insights for future advancements in this field. [ABSTRACT FROM AUTHOR]

Rate coefficients, k(T), for the gas‐phase OH radical reaction with decamethyltetrasiloxane ((CH3)3SiO[Si(CH3)2O]2Si(CH3)3, L4, k1), dodecamethylpentasiloxane ((CH3)3SiO[Si(CH3)2O]3Si(CH3)3, L5, k2), and decamethylcyclopentasiloxane ([–Si(CH3)2O–]5, D5, k3), and dodecamethylcyclohexasiloxane ([–Si(CH3)2O–]6, D6, k4) were measured using a pulsed laser photolysis—laser induced fluorescence absolute method over the temperature range 270–370 K. The obtained room temperature rate coefficients, with quoted 2σ absolute uncertainties, and fitted temperature dependence are (cm−3 molecule−1 s−1): k1295K=2.50±0.18×10−12,k1270−370K=1.707×10−13T/2984.45exp807/Tk2295K=3.12±0.32×10−12,k2295−370K=2.65±0.02×10−11exp−630±60/Tk3295K=2.02±0.12×10−12,k3270−370K=8.97×10−13T/2982.90exp248/Tk4297K=2.89±0.16×10−12,k4297−370K=3.13±0.05×10−11exp−717±119/T$$\begin{equation*} \hspace*{45pt} \def\eqcellsep{&}\begin{array}{rcl} {k}_1\left( {295\;{\mathrm{K}}} \right) &=& \left( {2.50 \pm 0.18} \right) \times {{10}}^{ - 12},\quad {k}_1\left( {270-370\;{\mathrm{K}}} \right)\\ & =& 1.707 \times {{10}}^{ - 13}{{\left( {{\mathrm{T}}/298} \right)}}^{4.45}\exp \left( {807/{\mathrm{T}}} \right)\\ {k}_2\left( {295\;{\mathrm{K}}} \right) &=& \left( {3.12 \pm 0.32} \right) \times {{10}}^{ - 12},\quad {k}_2\left( {295-370\;{\mathrm{K}}} \right)\\ &=& \left( {2.65 \pm 0.02} \right) \times {{10}}^{ - 11}\exp \left( { - \left( {630 \pm 60} \right)/{\mathrm{T}}} \right)\\ {k}_3\left( {295\;{\mathrm{K}}} \right) &=& \left( {2.02 \pm 0.12} \right) \times {{10}}^{ - 12},\quad {k}_3\left( {270-370\;{\mathrm{K}}} \right)\\ & =& 8.97 \times {{10}}^{ - 13}{{\left( {T/298} \right)}}^{2.90}\exp \left( {248/{\mathrm{T}}} \right)\\ {k}_4\left( {297\;{\mathrm{K}}} \right) &=& \left( {2.89 \pm 0.16} \right) \times {{10}}^{ - 12},\quad {k}_4\left( {297-370\;{\mathrm{K}}} \right)\\ & =& \left( {3.13 \pm 0.05} \right) \times {{10}}^{ - 11}\exp \left( { - \left( {717 \pm 119} \right)/{\mathrm{T}}} \right) \end{array} \end{equation*}$$The 2σ absolute rate coefficient uncertainty, for all compounds included in this study, is conservatively estimated to be ∼10% over the entire temperature range. The cyclic permethylsiloxanes were found to be less reactive than the analogous linear compound, while both linear and cyclic compounds show increasing reactivity with increasing number of CH3‐ groups. A structure activity relationship (SAR) parameterization for the permethylsiloxanes is presented. The estimated atmospheric lifetimes due to OH reaction for L4, L5, D5, and D6 are 5.2, 4.4, 6.8, and 5.2 days, respectively. [ABSTRACT FROM AUTHOR]

Despite the remarkable luminescent properties and temperature sensing capabilities of lanthanide materials, their photothermal effect in practical temperature measurement systems presents a major challenge to sensing reliability. Herein, taking Pr3+ as a typical exemplar, the influence of excitation wavelength and excitation approach on temperature sensing is systematically examined. The pulsed laser excitation method is identified as an efficient tactic to restrain the self‐heating of luminescence materials. In accordance with this principle, it is discovered that diverse excitation wavelengths give rise to alterations in the internal energy transport channels and further impact the temperature sensing performance. The 980 nm pulsed laser can result in the non‐thermal coupling occupying states of 3P0/3P1, which are recognized as thermal coupling energy levels in the conventional concept, and yield a relative sensitivity (Sr) performance more than three times superior to that of down‐shifting‐based sensing. The work provides a comprehensive analytical solution for achieving highly sensitive and stable temperature sensing based on excitation wavelength and working mode strategies. [ABSTRACT FROM AUTHOR]

A retrospective study published in Lasers in Medical Science examined the treatment of Mibelli angiokeratoma using pulsed dye laser (PDL) on 21 patients. The study, conducted at the Laser Center of Hospital for Skin Diseases, Shandong First Medical University, showed a high success rate with 95.24% of patients experiencing significant improvement or recovery after 1-3 PDL treatments. The treatment parameters and outcomes varied based on the location of the lesions, with hand lesions showing the most effective response. Adverse reactions such as purpura, pain, and edema were common but temporary. The study concluded that PDL treatment for angiokeratoma was safe, effective, and well-tolerated by patients. [Extracted from the article]

Measurements of the output optical power, laser-oscillation spectra, optical-pulse duration, and switching-on delays of semiconductor lasers–thyristors with a strip width of 200 μm and a length of 980 μm were performed in the operating temperature range from 20 to 70°C at a nominal value of the discharge capacitor of 22 nF and a control-current amplitude of 10.4 mA. It is shown that lasers–thyristors have high temperature stability. When the devices were heated from 20 to 70°C, the level of reduction of the peak output power did not exceed 15% for supply voltages of 4–20 V and 25% for a voltage of 3 V; the shift of the central wavelength of the oscillation spectrum was on average 0.21 nm/°C. [ABSTRACT FROM AUTHOR]

In this work, we have investigated the resistive switching (RS) properties of metal-insulator-metal (MIM) RRAM (resistive random-access memory) devices based on Hafnium Oxide (HfO2) films. A systematic study on the effect of substrate temperature on the crystallinity and its correlation with RS behaviour of HfO2 films deposited on platinized silicon using the Pulsed Laser Deposition (PLD) has been performed. Grazing-incidence X-ray diffraction and X-ray reflectivity techniques were employed to analyse the phase formation and the thickness of the films, respectively. The films were deposited at two different substrate temperatures 400 °C and 700 °C. A lower substrate temperature led to an amorphous film while the higher substrate temperature resulted in a polycrystalline film. The effect of change in amorphous to polycrystalline nature of HfO2 films with substrate temperature was studied on RS behaviour of these films. To assess the RS behaviour, DC electrical characterization was conducted on stacked W/HfO2/Pt thin films. The electrical characterization revealed forming-free bipolar RS behavior in both the films along with a digital SET and gradual RESET. The resistance of the films was found to be dependent on phase and microstructure which in turn depends upon substrate temperature. This study would be useful for the optimization of RS behaviour by tuning the crystallinity of the HfO2 films through processing temperature. [ABSTRACT FROM AUTHOR]

This paper showcases the development of CuO nanoparticles (CuO NPs) deocrated on the surface of carbon nanotubes (CNTs) in polymer nanofiber structure. Both pulsed laser ablation and electrospinning were used to form decorated CNTs electrospun nanofibrous membrane. These technologies combine the decorated CNTs with electrospinning to create multifunctional membranes from polyurethane (PU) in a straightforward and cost-efficient manner. Different techniques were used to confirm the results. Simultaneously, we observed the morphological features and the particle size of the decorated CuO using scanning and transmission electron microscopy (SEM and TEM) with energy-dispersive X-ray spectroscopy (EDX). XRD analysis revealed sharp diffraction peaks, indicating the high crystalline structure of CuO NPs grown alongside nanotubes. Additionally, the presence of PU in the diffractogram showed minimal difference in the peak strength of the polyurethane matrix. FT-IR analysis also showed unique peaks that confirmed the substitution of graphite structure of CNTs, which shows that the successful decoration of metal oxide. In terms of catalytic performance, the produced samples demonstrated high efficiency in completing the reduction of 4-nitrophenol, particularly when CuO nanoparticles adorned the outer surface of CNTs in the membrane structure. This confirms the potential of using CuO/CNTs/PU nanofibrous membrane in significant quantities to enhance efficiency against hazardous compounds. [ABSTRACT FROM AUTHOR]

Nowadays, the development of devices based on organic materials is an interesting research challenge. The performance of such devices is strongly influenced by material selection, material properties, design, and the manufacturing process. Usually, buckminsterfullerene (C60) is employed as electron transport material in organic photovoltaic (OPV) devices due to its high mobility. However, considering its low solubility, there have been many attempts to replace it with more soluble non-fullerene compounds. In this study, bulk heterojunction thin films with various compositions of zinc phthalocyanine (ZnPc), a perylene diimide derivative, or C60 were prepared by matrix-assisted pulsed laser evaporation (MAPLE) technique to assess the influence of C60 replacement on fabricated heterostructure properties. The investigations revealed that the optical features and the electrical parameters of the organic heterostructures based on this perylene diimide derivative used as an organic acceptor were improved. An increase in the JSC value (4.3 × 10−4 A/cm2) was obtained for the structures where the perylene diimide derivative acceptor entirely replaced C60 compared to the JSC value (7.5 × 10−8 A/cm2) for the heterostructure fabricated only with fullerene. These results are encouraging, demonstrating the potential of non-fullerene compounds as electron transport material in OPV devices. [ABSTRACT FROM AUTHOR]

The current strategy for treating osteomyelitis includes surgical procedures for complete debridement of the formed biofilm and necrotic tissues, systemic and oral antibiotic therapy, and the clinical use of cements and three-dimensional scaffolds as bone defect fillers and delivery systems for therapeutic agents. The aim of our research was to formulate a low-cost hybrid nanoparticulate biomaterial using poly(lactic-co-glycolic acid) (PLGA), in which we incorporated the therapeutic agent (ciprofloxacin), and to deposit this material on titanium plates using the matrix-assisted pulsed laser evaporation (MAPLE) technique. The deposited material demonstrated antibacterial properties, with all analyzed samples inhibiting the growth of tested bacterial strains, confirming the release of active substances from the investigated biocomposite. The poly(lactic-co-glycolic acid)-ciprofloxacin (PLGA-CIP) nanoparticle scaffolds displayed a prolonged local sustained release profile over a period of 45 days, which shows great promise in bone infections. Furthermore, the burst release ensures a highly efficient concentration, followed by a constant sustained release which allows the drug to remain in the implant-adjacent area for an extended time period. [ABSTRACT FROM AUTHOR]

Objectives: To assess laser–tissue interactions through ablation, coagulation, and carbonisation characteristics in a non‐perfused porcine kidney model between three pulsed lasers: holmium (Ho): yttrium‐aluminium‐garnet (YAG), thulium fiber laser (TFL), and pulsed thulium (p‐Tm):YAG. Materials and Methods: A 150‐W Ho:YAG, a 60‐W TFL, and a 100‐W p‐Tm:YAG lasers were compared. The laser settings that can be set identically between the three lasers and be clinically relevant for prostate laser enucleation were identified and used on fresh, unfrozen porcine kidneys. Laser incisions were performed using stripped laser fibers of 365 and 550 μm, set at distances of 0 and 1 mm from the tissue surface at a constant speed of 2 mm/s. Histological analysis evaluated shape, depth, width of the incision, axial coagulation depth, and presence of carbonisation. Results: Incision depths, widths, and coagulation zones were greater with Ho:YAG and p‐Tm:YAG lasers than TFL. Although no carbonisation was found with the Ho:YAG and p‐Tm:YAG lasers, it was common with TFL, especially at high frequencies. The shapes of the incisions and coagulation zones were more regular and homogeneous with the p‐Tm:YAG laser and TFL than with Ho:YAG laser. Regardless of the laser used, short pulse durations resulted in deeper incisions than long pulse durations. Concerning the distance, we found that to be effective, TFL had to be used in contact with the tissue. Finally, 365‐μm fibers resulted in deeper incisions, while 550‐μm fibers led to wider incisions and larger coagulation zones. Conclusion: Histological analysis revealed greater tissue penetration with the p‐Tm:YAG laser compared to the TFL, while remaining less than with Ho:YAG. Its coagulation properties seem interesting insofar as it provides homogeneous coagulation without carbonisation, while incisions remained uniform without tissue laceration. Thus, the p‐Tm:YAG laser appears to be an effective alternative to Ho:YAG and TFL lasers in prostate surgery. [ABSTRACT FROM AUTHOR]

In the field of precision machining, with the popularity of brittle and hard materials such as infrared windows, it has become difficult for conventional diamond grinding wheels to effectively perform high-quality machining. The structuring of traditional diamond grinding wheels using a pulsed laser is a key technology to effectively improve the grinding quality of grinding wheels. In this paper, three new shark fin diamond grinding wheels (SFSGW) with different slot widths are designed based on the excellent drag-reducing and channelizing properties of shark dorsal fins. The grinding performance of traditional grinding wheels (USGW) and SFSGW on magnesium fluoride ceramics was compared. The effects of SFSGW on the surface quality, surface roughness and wheel damage of the workpiece were investigated. The results showed that the surface roughness of ceramics after grinding by SFSGW was reduced by 22.15 % compared with USGW, and the surface quality was better. Proper construction increases the material removal rate of the wheel and improves the wear resistance and service life of the wheel. [ABSTRACT FROM AUTHOR]

We introduce a method utilizing single laser-generated cavitation bubbles to stimulate cellular mechanotransduction in dermal fibroblasts embedded within 3D hydrogels. We demonstrate that fibroblasts embedded in either amorphous or fibrillar hydrogels engage in Ca2+ signaling following exposure to an impulsive mechanical stimulus provided by a single 250 µm diameter laser-generated cavitation bubble. We find that the spatial extent of the cellular signaling is larger for cells embedded within a fibrous collagen hydrogel as compared to those embedded within an amorphous polyvinyl alcohol polymer (SLO-PVA) hydrogel. Additionally, for fibroblasts embedded in collagen, we find an increased range of cellular mechanosensitivity for cells that are polarized relative to the radial axis as compared to the circumferential axis. By contrast, fibroblasts embedded within SLO-PVA did not display orientation-dependent mechanosensitivity. Fibroblasts embedded in hydrogels and cultured in calcium-free media did not show cavitation-induced mechanotransduction; implicating calcium signaling based on transmembrane Ca2+ transport. This study demonstrates the utility of single laser-generated cavitation bubbles to provide local non-invasive impulsive mechanical stimuli within 3D hydrogel tissue models with concurrent imaging using optical microscopy. Currently, there are limited methods for the non-invasive real-time assessment of cellular sensitivity to mechanical stimuli within 3D tissue scaffolds. We describe an original approach that utilizes a pulsed laser microbeam within a standard laser scanning microscope system to generate single cavitation bubbles to provide impulsive mechanostimulation to cells within 3D fibrillar and amorphous hydrogels. Using this technique, we measure the cellular mechanosensitivity of primary human dermal fibroblasts embedded in amorphous and fibrillar hydrogels, thereby providing a useful method to examine cellular mechanotransduction in 3D biomaterials. Moreover, the implementation of our method within a standard optical microscope makes it suitable for broad adoption by cellular mechanotransduction researchers and opens the possibility of high-throughput evaluation of biomaterials with respect to cellular mechanosignaling. [Display omitted] [ABSTRACT FROM AUTHOR]

We report an application of a pulsed ultraviolet (UV) laser (λ = 355 nm) in producing translucent Si solar cells. This process efficiently generates a densely packed microhole array on a fully fabricated Si P‐N junction solar cell in just a few minutes. Herein, prototype cells with a nominal microhole diameter of 23 μm with a spacing between 60 and 300 μm are fabricated. High‐resolution electron‐beam microscopy reveals that the UV laser beam introduces amorphized silicon oxide (SiOx) in proximity to the patterned microholes via localized heating in air. Quantitative photovoltaic (PV) analysis shows a decline in the open‐circuit voltage (Voc) and the fill factor (FF) of the cells with the increase in the microhole density, likely due to the P‐N junction damage during the laser beam irradiation. Despite the reduction in Voc and FF, the solar cells retain a short‐circuit current density (Jsc) above 90% without post‐processing. The inherent microhole geometry associated with the laser beam profile allows multiple light scattering within the confined microhole structure, enhancing the translucency of the cells. While further development is required for optimization, these findings support the potential use of UV laser beams for fast and scalable production of translucent solar cells. [ABSTRACT FROM AUTHOR]

Jellyfish stings can cause acute inflammatory skin lesions that may hesitate in keloids. Pulsed dye laser (PDL) represents one of the most effective treatments for newly developed keloids. Aim of this study was to evaluate the efficacy of PDL on newly developed keloids specifically induced by jellyfish stings in pediatric patients.We conducted a retrospective observational study on pediatric patients with newly developed keloids from jellyfish stings, treated in the last two years with 595 nm wavelength PDL with a duration of 0.45–1.5 msec, spot-size 7 mm and fluence 8.5–9.5 J/cm2. PDL therapy was administered for a mean of 7.4 treatment sessions, every 1–3 months. Two expert dermatologists evaluated the vascularity, pigmentation, height, and pliability of keloids, according to the Vancouver Scar Scale (VSS), pre-and-post treatment. A total of 17 patients (7 males, 10 females) were included in the study, mean age of 11 years. Overall, mean pre-treatment global VSS was 11.0 ± 1.50. After treatment, global VSS was 3.88 ± 1.87. At paired t-test, the difference between pre-treatment and post-treatment was highly statistically significant (p < .0001). Commonly, manipulation and therapeutic intervention on jellyfish scars and keloids is feared. The present study supports the use of PDL in keloids secondary to jellyfish stings, though conducted on a limited number of patients. [ABSTRACT FROM AUTHOR]

The generation of pressure perturbations in matter stimulated by pulsed light is a method widely recognized as the photoacoustic or light‐induced thermoelastic effect. In a series of psychophysical experiments, the robustness of the tactile perception generated with a variety of light sources is examined: a diverging pulsed laser used for photoacoustic tomography optical parameter oscillation (OPO), a miniature diode laser (MDL), and a commercial digital light processing (DLP) projector. It is demonstrated that participants can accurately detect, categorically describe the sensations, and discern the direction of pulsed light travel. High detection accuracy is reported as follows: (d′ = 4.95 (OPO); d′ = 2.78 (modulated MDL); d′ = 2.99 (DLP)) of the stimulus on glabrous skin coated with a thin layer of dye absorber. For all light sources, the predominant sensation is felt as vibration at the distal phalanx (i.e., fingertip, 55.21–57.29%) and the proximal phalanx (41.67–44.79%). At the fingertip, thermal sensations are perceived less frequently than mechanical ones. Moreover, these haptic effects are preserved under a wide range of pulse widths, spot sizes, optical energies, and wavelengths of the light sources. This form of sensory stimulation demonstrates a generalizable non‐contact, non‐optogenetic, in situ activation of the mechanosensory system. [ABSTRACT FROM AUTHOR]

In this work, the nonlinear optical (NLO) properties of CuO nanoparticles (CuO NPs) were studied experimentally using the pulsed laser ablation (PLA) technique. A nanosecond Nd: YAG laser was employed as the ablation excitation source to create CuO NPs in distilled water. Various CuO NPs samples were prepared at ablation periods of 20, 30, and 40 min. Utilizing HR-TEM, the structure of the synthesized CuO NPs samples was verified. In addition, a UV–VIS spectrophotometer was used to investigate the linear features of the samples. The Z-scan technique was utilized to explore the NLO properties of CuO NPs samples, including the nonlinear absorption coefficient (β) and nonlinear refractive index ( n 2 ). An experimental study on the NLO features was conducted at a variety of excitation wavelengths (750–850 nm), average excitation powers (0.8–1.2 W), and CuO NPs sample concentrations and sizes. The reverse saturable absorption (RSA) behavior of all CuO NPs samples differed with the excitation wavelength and average excitation power. In addition, the CuO NPs samples demonstrated excellent optical limiters at various excitation wavelengths, with limitations dependent on the size and concentration of CuO NPs. [ABSTRACT FROM AUTHOR]

Halide perovskite materials have garnered significant research attention due to their remarkable performance in both photoharvesting photovoltaics and photoemission applications. Recently, self-assembled CsPbBr3 superstructures (SSs) have been demonstrated to be promising lasing materials. In this study, we report the ultrastable two-photon-pumped amplified stimulated emission from a CsPbBr3 SS/Ag hybrid microcavity with a low threshold of 0.8 mJ/cm2 at room temperature. The experimental results combined with numerical simulations show that the CsPbBr3 SS exhibits a significant enhancement in the electromagnetic properties in the hybrid microcavity on Ag film, leading to the uniform spatial temperature distribution under the irradiation of a pulsed laser, which is conducive to facilitate the recrystallization process of the QDs and improve their structural integrity and optical properties. This study provides a new idea for the application of CsPbBr3/Ag hybrid microcavity in photonic devices, demonstrating its potential in efficient optical amplification and upconversion lasers. [ABSTRACT FROM AUTHOR]

Recent progress has seen multiple Ta2O5 polymorphs generated by different synthesis techniques. However, discrepancies arise when these polymorphs are produced in widely varying thermodynamic conditions and characterized using different techniques. This work aimed to characterize and compare Ta2O5 particles formed at high and low temperatures using nanosecond pulsed laser ablation (PLA) and continuous wave (CW) laser heating of a local area of tantalum in either air or an 18O2 atmosphere. Scanning electron microscopy (SEM) and Raman spectroscopy of the micrometer-sized particles generated by PLA were consistent with either a localized amorphous Ta2O5 phase or a similar, but not identical, crystalline β-Ta2O5 phase. The Raman spectrum of the material formed at the point of CW laser impingement was in good agreement with the previously established ceramic "H-Ta2O5" phase. TEM and electron diffraction analysis of these particles indicated the phase structure matched an oxygen-vacated superstructure of monoclinic H-Ta2O5. Further from the point of laser impingement, CW heating produced particles with a Raman spectrum that matched β-Ta2O5. We confirmed that the high-temperature ceramic phase characterized in previous work by Raman spectroscopy was the same monoclinic phase characterized in different work by TEM and could be produced by direct laser heating of metal in air. [ABSTRACT FROM AUTHOR]

Phase change materials (PCMs) have gained a tremendous interest as a means to actively tune nanophotonic devices through the large optical modulation produced by their amorphous to crystalline reversible transition. Recently, materials such as Sb2S3 emerged as particularly promising low loss PCMs, with both large refractive index modulations and transparency in the visible and near‐infrared. Controlling the local and reversible phase transition in this material is of major importance for future applications, and an appealing method to do so is to exploit pulsed lasers. Yet, the physics and limits involved in the optical switching of Sb2S3 are not yet well understood. Here, the reversible laser‐induced phase transition of Sb2S3 is investigated, focusing specifically on the mechanisms that drive the optically induced amorphization, with multi‐physics considerations including the optical and thermal properties of the PCM and its environment. The laser energy threshold for reversibly changing the phase of the PCM is determined through both theoretical analysis and experimental investigation, not only between fully amorphous and crystalline states but also between partially recrystallized states. Then, the non‐negligible impact of the material's polycrystallinity and anisotropy on the power thresholds for optical switching is revealed. Finally, the challenges related to laser amorphization of thick Sb2S3 layers are addressed, as well as strategies to overcome them. These results enable a qualitative and quantitative understanding of the physics behind the optically‐induced reversible change of phase in Sb2S3 layers. [ABSTRACT FROM AUTHOR]

Accurate three-dimensional spatiotemporal distribution information on near-surface aerosols is of great significance for environmental research. In this study, a 3D scanning coaxial Mie lidar (3D-STML) was developed to achieve a fast three-dimensional scanning observation of aerosol diffusion processes in near-surface areas. 3D-STML generates high-spatiotemporal resolution images of aerosol extinction coefficient in real-time and captures the dynamic changes of aerosols in near real-time. By optimizing the design of the light guide mirror and the telescope sub-mirror, the system has a small overlap. Based on this, a highly stable and high-speed mechanical rotation mechanism was developed to enable three-dimensional observations. The integration of a solid-state high-repetition-rate pulsed laser and a coaxial, optical system for the transmitter and receiver ensures rapid tracking of aerosol plumes. To meet the observation requirements of near-surface aerosols, an aerosol inversion algorithm combining the Fernald and Klett methods was designed and developed. For aerosol plume monitoring needs, an aerosol plume-tracking algorithm based on Kalman filtering was developed to track the spatiotemporal evolution of aerosols automatically. Experimental results demonstrated that 3D-STML is capable of detecting aerosols in a range from 15 m to 4 km, with a distance resolution of 1.5 m and a time resolution of 0.083 s. It can effectively track and capture aerosol plumes. It can be used for large-scale, long-term observation of near-surface aerosols and for monitoring the spatiotemporal evolution of aerosol plumes. [ABSTRACT FROM AUTHOR]

In this study we introduce photoluminescence analysis of nano powder YAlO3 doped with Er3+ and Yb3+. We compare this material with other hosts, Gd2O3, CaGdAlO4 and Y2O2S, doped with Er3+ and Yb3+. Beside usual ways to characterize these materials we also include visual comparison by data dimensionality reduction techniques, as a way for initial assessment of a new material. Samples were excited at 980 nm by using pulsed laser diode to analyze effects of host matrices on optical emission of erbium. For this purpose the luminescence spectra of all samples were obtained in a continuous series of measurements under the same experimental conditions. Moreover, the samples were prepared in the same way, by combustion synthesis. We compare the possibilities of using these materials for remote temperature sensing, showing that YAlO3:Er3+, Yb3+ is a good candidate for remote temperature sensing. [ABSTRACT FROM AUTHOR]

In this work, Fe3O4 nanoparticles (NPs) were successfully created via utilizing pulsed laser ablation in deionized water. Utilizing Nd: YAG laser with various wavelengths (532, 1064 nm) and laser fluencies (22, 23, 26 J/cm2). The generated nanoparticles' structure and optical characteristics were investigated. The nanoparticles were studied by utilizing UV–vis spectroscopy, dynamic light scattering (DLS), magnetization hysteresis loop, atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray diffraction pattern (XRD). The values of Fe3O4 NPs' optical bandgap were 2.4 eV for laser wavelength 1064 nm and 2.5 eV for laser wavelength 532 nm. The obtained nanoparticles exhibited high saturation magnetization (45 and 60 emu/g) for the synthesis nanoparticles at the laser wavelengths 1064 and 532 nm, respectively. The results of XRD exhibited the production of Fe3O4 nanoparticles and have high purity crystalline with a cubic spinel structure. The results of SEM showed crystals morphologically and a uniform size distribution of the synthesis NPs with average sizes of about (65 and 30 nm) for the synthesis nanoparticles at the laser wavelengths 1064 and 532 nm, respectively. This study focuses on the preparation, properties, and application of iron oxide nanoparticles (IONPs) synthesized through PLAIL for methylene blue (MB) dye degradation processes and the antibacterial activity of the prepared nanoparticles against Gram-positive: Staphylococcus aureus. The PLAIL method enables the production of tunable iron oxide nanoparticles (IONPs) with controlled size, morphology, and surface properties. The experimental setup, synthesis procedure, characterization techniques, photo-catalytic performance, and antibacterial activity are discussed. The results highlight the significance of PLAIL-synthesized IONPs in damage and inhibit bacterial growth, pollutant degradation, and the potential for future environmental remediation applications. [ABSTRACT FROM AUTHOR]

In the present communication, structural and electrical properties of Y0.95Ca0.05MnO3 (YCMO) manganite thin films, having different thicknesses grown on (100) single crystalline Nb:SrTiO3 (SNTO) substrate using pulsed laser deposition (PLD) technique, have been investigated. Influence of 100 MeV O+7 energetic ion irradiation has been understood on the basis of structure–property correlations across the lattice of YCMO manganite. Influence of YCMO film thickness and ion fluence on the electrical properties have also been explored in the context of lattice strain, crystallite size (CS), crystallinity, defect state, local annealing effect and three dimensional disorder. YCMO/SNTO interface experiences the presence of tensile strain which is found to vary between +1.02 and +1.88% for 100 nm YCMO/SNTO thin film whereas it is found to decrease monotonically from +1.50 to +0.98% for 200 nm and +1.40 to +0.92% for 300 nm upon increase in ion fluence. For higher thicknesses of YCMO/SNTO films (i.e. 200 and 300 nm), CS (estimated using Scherrer's formula) is found to increase from 19.73 nm for pristine to 25.01 nm for higher influence irradiated 200 nm film and from 24.91 nm for pristine to 27.97 nm for higher influence irradiated 300 nm film which has been ascribed to the local annealing effect across the YCMO/SNTO thin film lattices. Variation in dielectric constant with frequency, YCMO layer thickness and ion fluence has been understood on the bases of lattice strain, defect state, CS, crystallite boundaries, dipolar relaxation and universal dielectric response (UDR) model. Nature of ac conductivity has been understood well in the context of Jonscher's power law fits where correlated barrier hopping (CBH) mechanism has been confirmed as a responsible process for charge conduction across the YCMO/SNTO interfaces. Maximum barrier height (Wm) has been derived using its relation with power exponent from Jonscher's power law fits to ac conductivity data and its values are found to vary nonmonotonically between 0.3218 and 0.4849 eV for 100 nm YCMO/SNTO film however it gets enhanced from 0.2382 to 0.3820 eV for 200 nm and from 0.1977 to 0.2203 eV for 300 nm YCMO/SNTO films upon increase in oxygen ion fluence. These variations have been ascribed to the dominant impact of high resistive insulating nature of core of the YCMO crystallites and three dimensional disorder across YCMO manganite lattice. Present report serves a complex simultaneous impact of YCMO layer thickness, ion fluence and related structural aspects on the electrical properties of YCMO/SNTO films where defect state can be regenerated through well established experimental tool of SHI irradiation in a controlled way. The electric properties of YCMO/SNTO thin films are of paramount importance in a variety of technological applications and are of fundamental importance for materials science research. [ABSTRACT FROM AUTHOR]

In printed electronics, nanosecond pulsed laser scanning ablation is used to repair misprinted conductive silver (Ag) nanoparticle (NP) lines. Nanosecond-pulsed laser ablation is a thermal process influenced by the thermal dissipation of the substrate. In this study, we investigated the influence of the thermal properties of the substrate on the scanning ablation of Ag NP layers using a 532 nm Nd:YAG laser. We examined the ablation aspects of nanosecond pulsed scanning ablation of Ag NP layers on polyimide (PI), glass, and crystalline silicon (Si) substrates. The dried Ag NP layers and Ag NP layers that were sintered at 100, 150, and 200 °C were compared. No significant difference was observed between the ablation thresholds of the Ag NP on PI and glass substrates at all sintering temperatures. However, when the sintering temperature was 150 and 200 °C, the ablation thresholds of Ag NP on Si substrate were 371 and 435 mJ/cm2, which are noticeably larger than the 284 and 355 mJ/cm2 of 150 and 200 °C sintered Ag NP on PI substrate and 273 and 349 mJ/cm2 of 150 and 200 °C sintered Ag NP on glass substrate. Qualitative and quantitative explanations of the observed trends were provided. [ABSTRACT FROM AUTHOR]

Laser doping of silicon with pulsed and scanned laser beams is now well-established to obtain defect-free, doping profile tailored, and locally selectively doped regions with a high spatial resolution. Picking the correct laser parameters (pulse power, pulse shape, and scanning speed) impacts the depth and uniformity of the melted region geometry. This work performs laser doping on the surface of single crystalline silicon, using a pulsed and scanned laser profile with a Gaussian intensity distribution. A deposited boron oxide precursor layer serves as a doping source. Increasing the local inter-pulse distance x irr between subsequent pulses causes a quadratic decrease of the sheet conductance G sh of the doped surface layer. Here, we present a simple geometric model that explains all experimental findings. The quadratic dependence stems from the approximately parabolic shape of the individual melted regions directly after the laser beam has hit the Si surface. The sheet resistance depends critically on the intersection depth d ch and the distance x irr of overlap between two subsequent, neighboring pulses. The intersection depth d ch quadratically depends on the pulse distance x irr and therefore also on the scanning speed v scan of the laser. Finally, we present a simple model that reduces the complicated three dimensional, laterally inhomogeneous doping profile to an effective two-dimensional, homogeneously doped layer which varies its thickness with the scanning speed. [ABSTRACT FROM AUTHOR]

In recent years, academic research on perovskite solar cells (PSCs) has attracted remarkable attention, and one of the most crucial issues is promoting the power conversion efficiency (PCE) and operational stability of PSCs. Generally, modification of the electron or hole transport layers between the perovskite layers and electrodes via surface engineering is considered an effective strategy because the inherent structural defects between charge carrier transport layers and perovskite layers can be reshaped and modified by adopting the functional nanomaterials, and thus the charge recombination rate can be naturally decreased. At present, large amounts of available nanomaterials for surface modification of the perovskite films are extensively investigated, mainly including nanocrystals, nanorods, nanoarrays, and even colloidal quantum dots (QDs). In particular, as unique size-dependent nanomaterials, the diverse quantum properties of colloidal QDs are different from other nanomaterials, such as their quantum confinement effects, quantum-tunable effects, and quantum surface effects, which display great potential in promoting the PCE and operational stability of PSCs as the charge carriers in perovskite layers can be effectively tuned by these quantum effects. However, preparing QDs with a neat and desirable size remains a technical difficulty, even though the present chemical engineering is highly advanced. Fortunately, the rapid advances in laser technology have provided new insight into the precise preparation of QDs. In this review, we introduce a new approach for preparing the QDs, namely pulsed laser irradiation in colloids (PLIC), and briefly highlight the innovative works on PLIC-prepared QDs for the optimization of PSCs. This review not only highlights the advantages of PLIC for QD preparation but also critically points out the challenges and prospects of QD-based PSCs. [ABSTRACT FROM AUTHOR]

Pulsed solid‐state lasers comprise 2D materials as saturable absorbers that contain transparent windows of the atmosphere and characteristic fingerprint spectra of several vital molecules that are significant in various applications and research. Over the past few decades, significant progress has been made in the development of narrow pulse width, high energy, high average output power, high efficiency, and simple construction of passively Q‐switched and mode‐locked lasers with 2D materials as saturable absorbers. This review summarizes the development of 2D materials, including graphene, transition metal dichalcogenides, black phosphorus, topological insulators, and MXenes, as modulator devices for solid‐state lasers owing to their broadband operation, excellent nonlinear optical response, low recovery time, ultrafast dynamic processing, and easy fabrication. Then, some new emerging and representative applications of pulsed solid‐state lasers are introduced and illustrated such as laser surgery, material processing, and lidar. Finally, future challenges and perspectives of pulsed solid‐state lasers with 2D materials‐based saturable absorbers are analyzed and addressed. The rapid development of pulsed solid‐state lasers with the continuous improvement of modulation technology is expected to expand opportunities for application in industry, scientific, medical, and other areas. [ABSTRACT FROM AUTHOR]

Many of the CM carbonaceous chondrites are regolith breccias and so should have abundant evidence for collisional processing. The constituent clasts of these fragmental rocks frequently display compactional petrofabrics; yet, olivine microstructures show that most CMs are unshocked. To better understand the reasons for this contradiction, we have sought other evidence for hypervelocity impact processing of CM chondrites using the Cold Bokkeveld meteorite. We find that this regolith breccia contains rare particles of vesicular shock melt that are close in chemical composition to bulk CM chondrite. Transmission electron microscopy of a melt bead shows that it is composed of silicate glass with inclusions of pentlandite, pyrrhotite, and wüstite. Characterization of shards of another bead by atom probe tomography reveals nanoscale clusters of sulfur that represent sulfide inclusions arrested at an early stage of growth. These glass particles are mineralogically comparable to micrometeoroid impact melt described from the Cb‐type asteroid Ryugu and melt that has been experimentally produced by pulsed laser irradiation of CM targets. The glass could have formed by in situ shock‐melting, but petrographic evidence is more consistent with an origin as ballistic ejecta from a distal impact. The scarcity of melt in this meteorite, and CM chondrites more broadly, is consistent with the explosive fragmentation of hydrous asteroids following energetic collisions. Cold Bokkeveld's parent body is likely to be a second‐generation asteroid that was constructed from the debris of one or more earlier bodies, and only a small proportion of the reaccreted material had been highly shocked and melted. [ABSTRACT FROM AUTHOR]

Laser corneal reshaping is a safe and effective technique utilized to treat common vision disorders. An advanced laser delivery system equipped with a pulsed UV laser with specific parameters is used to ablate parts of the cornea surface to correct the existing refractive error. The argon fluoride (ArF) excimer pulsed gas laser at 193 nm is the most employed type in the commercial devices for such treatments. This laser is generated using a mixture of Argon, Fluorine, and a significant amount of Neon gases. However, due to the ongoing Russian‐Ukraine war, the availability of Neon gas is currently very limited, as this region is considered the primary supplier of pure Neon gas. Consequently we suggest replacing the common ArF laser source in the commercial devices with a solid‐state (forth harmonic neodymium‐doped yttrium aluminum garnet laser at 266 nm). This replacement uses the same operation parameters, optics, and scanning algorithm. Parameters from five commercial devices (Zeiss MEL 90, Technolas TENEO 317, Alcon Wave Light EX 500, Schwind Amaris 750 s, OptoSystems MICROSCAN VISUM) were compared with those of the i‐ablation device, a research device that uses a 266 nm laser source. Our goal is to reduce production costs through a simple modification that has a significant impact. Consequently, the present study aims to find an alternative laser source for the current ArF laser without exchanging the complete system's design. This recommendation is based on a numerical simulation study. The thermal effect on a human cornea model was numerically evaluated using finite‐element solutions of Pennes' bioheat equation on the COMSOL platform by applying two laser wavelengths. The results demonstrated that changing the laser source significantly impacts the thermal effect, even with the same laser settings. All studied devices showed a reduction in the thermal effect to below 40°C, compared with nearly 100°C under ordinary conditions. [ABSTRACT FROM AUTHOR]

A Pulsed ns laser operating at 532 nm wavelength with 150 mJ pulse energy was employed to irradiate micrometric thick mylar films, from 1 to 100 μm thick, covered by 0.05 μm Au in the back face. Protons and light ions have been accelerated by the electric field developed in the non‐equilibrium plasma by the laser pulse in a vacuum at an intensity of the order of 1010 W/cm2. Time‐of‐flight technique, obtained using a Faraday cup and a fast storage oscilloscope, is employed to measure the ion velocity, energy, and yield emitted in backward and forward directions. The yield of the emitted plasma photons is also evaluated. Two ion collectors are used in opposite directions to measure the plasma radiations emitted in backward and forward directions. Data analysis is based on the Coulomb‐Boltzmann‐shifted (CBS) distribution function. The target ablation yield is evaluated in the order of 3.5 μm per laser shot. [ABSTRACT FROM AUTHOR]

• A pulsed laser method is used to debond ethylenevinylacetate polymer from silicon. • The glass/polymer layer can be separated from silicon in solar photovoltaic cells. • Nanosecond pulses at 355 nm and 532 nm are more effective than 1064 nm. • Transient surface melting does not damage the silicon wafer or metallic contacts. • Pulsed laser debonding can be applied to silicon photovoltaic panel recycling. The active silicon cell of a solar photovoltaic (PV) panel is covered by an ethylenevinylacetate (EVA) adhesive and a protective top glass layer. Separating this glass-EVA layer from the underlying silicon represents a bottleneck for recycling PV panels. Previous work has shown that the EVA-Si bond can be weakened by applying a continuous source of heat to melt the EVA. In this paper, a new method using nanosecond laser pulses is demonstrated to induce transient melting selectively at the EVA-Si interface. This impulsive heating method can cleanly separate the glass-EVA layer from the silicon in both model and commercial multicrystalline PV panels. The dependence of this debonding on parameters like laser pulse fluence (laser pulse energy per area), wavelength, applied pressure, and scan speed were characterized. For model PV panels, the single-pulse laser fluences required for spontaneous separation of the assembly under the force of gravity, were 0.23, 0.32 and 0.78 J/cm2 for 355 nm, 532 nm and 1064 nm, respectively. The use of shorter wavelengths reduces the laser fluence needed for debonding, while higher fluences can compensate for faster laser beam scanning rates. Optical and electron microscopy images of the Si surfaces before and after laser irradiation show that the textured antireflection layer is destroyed but the silver metal grid remains intact. Preliminary experiments using 532 nm pulses showed that the laser debonding method could remove the glass-EVA layer from sections of decommissioned commercial PV panels, even when the top glass layer was densely cracked. [ABSTRACT FROM AUTHOR]

The resent progress in the technology of transparent ceramics extends the application of CW and pulsed lasers. The parameters of the transparent ceramics are comparable with the single crystals both for active elements (Nd:YAG, Yb:YAG, etc.) and passive Q-switchers such as Cr4+:YAG. Despite the reaching of considerable progress, the sintering of Cr4+:YAG remains a challenge up to now. Up to the present the influence of the CaO, MgO and Cr 2 O 3 additives on the sintering process is poorly understander. Moreover, there is an absence of the unified model of Cr4+ ions formations in YAG ceramics. This factor limits the progress in the development of Cr4+:YAG ceramics. This review focused on the influence of the single additives and their combinations on the sintering trajectory of tetravalent chromium - doped YAG ceramics and the Cr4+ ions formation. [ABSTRACT FROM AUTHOR]

Although immunogenic cell death (ICD) induced by lysosomal membrane permeabilization (LMP) evidently enhance the effectiveness of antitumor immunity for triple-negative breast cancer (TNBC) with poor immunogenicity, their potential is increasingly restricted by the development of other death pathways and the repair of lysosomes by endoplasmic reticulum (ER) during LMP induction. Herein, a polydopamine nanocomposite with i-motif DNA modified and BNN6 loaded is prepared toward boosting LMP and immunotherapy of TNBC by synergy of spatially confined photoacoustic (PA) effects and nitric oxide. Combining the high-frequency pulsed laser (4000 kHz) with the intra-lysosomal assembly of nanocomposites produced spatially confined and significantly boosted PA effects (4.8-fold higher than the individually dispersed particles extracellular), suppressing damage to other cellular components and selectively reducing lysosomal integrity to 19.2 %. Simultaneously, the releasing of nitric oxide inhibited the repair of lysosomes by ER stress, causing exacerbated LMP. Consequently, efficient immune activation was achieved, including the abundant releasing of CRT/HMGB1 (5.93–6.8-fold), the increasing maturation of dendritic cells (3.41-fold), and the fostered recruitment of CD4+/CD8+ T cells (3.99–3.78-fold) in vivo. The study paves a new avenue for the rational design and synergy of confined energy conversion and responsive nanostructures to achieve the treatment of low immunogenicity tumors. A strategy of boosting lysosomal membrane permeabilization (LMP) and concomitantly preventing the repair was developed to address the immunotherapy challenge of triple-negative breast cancer. Spatially confined and significantly enhanced photoacoustic (PA) effects were achieved through DNA-guided pH-responsive assembly of polydopamine nanocomposites in lysosomes and application of a high-frequency pulsed laser. Efficient immunogenic cell death was guaranteed by selective and powerful damage of lysosomal membranes through the significant contrast of PA intensities for dispersed/assembled particles and nitric oxide release induced endoplasmic reticulum stress. The study paves a new avenue for the rational design and synergy of confined energy conversion and responsive nanostructures to achieve the treatment of low immunogenicity tumors. [Display omitted] [ABSTRACT FROM AUTHOR]

A sodium lidar (light detection and range) network for the Earth's mesosphere and lower thermosphere (MLT) temperature, wind and sodium density measurements is designed and constructed in the second phase of the Chinese Meridional Project. Five narrowband sodium lidar systems are deployed across various regions in China, designed and developed based on similar principles and structures. They adhere to uniform data processing standards and operate under the same observational protocols. This allows them to form a network of lidar systems capable of detecting temperature and wind fields in the MLT. The preliminary observation results of the lidar near Tibetan plateau is demonstrated in this paper. This lidar network offers horizontal perspectives on large scale that a single‐station lidar system can't provide. Its future observations are expected to advance the understanding of atmospheric waves by studying wave propagation, chemical‐dynamical coupling processes and the horizonal structure of in the MLT region. Plain Language Summary: This paper describes a new lidar (light detection and range) network to observe the mesosphere and lower thermosphere (MLT) region, which is the coldest area in the earth. Five narrow band sodium lidars in this network measure the temperature, wind and sodium density. They adhere to uniform data processing standards and follow the same observational protocols, which define the temporal and range resolution of lidar data, as well as the world geodetic system. The preliminary results for wind, temperature and sodium density are obtained. The lidar network will provide effective means for MLT research. Key Points: Narrowband sodium lidar based on pulsed seeder laser is constructed to measure wind and temperature in the mesosphere and lower thermosphere regionFive lidars distributed in the region of China from 19.5°N to 53.5°N, and from 87.2°E to 122.4°E form a lidar networkPreliminary observation results are demonstrated the ability and potential of the lidar network to conduct more scientific research [ABSTRACT FROM AUTHOR]

Herein, an in situ approach of pulsed laser irradiation in liquids (PLIL) was exploited to create surface‐modified electrodes for eco‐friendly H2 fuel production via electrolysis. The surface of the nickel foam (NF) substrate was nondestructively modified in 1.0 mol/L KOH using PLIL, resulting in a highly reactive Ni(OH)2/NF. Moreover, single‐metal Ir, Ru, and Pd nanoclusters were introduced onto Ni(OH)2/NF via appropriate metal precursors. This simultaneous surface oxidation of the NF to Ni(OH)2 and decoration with reduced metallic nanoparticles during PLIL are advantageous for promoting hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), and overall water splitting (OWS). The Ir‐Ni(OH)2/NF electrode demonstrates superior performance, achieving the lowest overpotentials at 10 mA/cm2 (η) with 74 mV (HER) and 268 mV (OER). The OWS using Ir‐Ni(OH)2/NF||Ir‐Ni(OH)2/NF cell demonstrated a low voltage of 1.592 V, reaching 10 mA/cm2 with notable stability of 72 h. Ir‐Ni(OH)2/NF performance is assigned to the improved defects and boosted intrinsic properties resulting from the synergy between metallic‐nanoparticles and the oxidized NF surface, which are positively influenced by PLIL. [ABSTRACT FROM AUTHOR]

A new diamond anvil cell experimental approach has been implemented at the European x-ray Free Electron Laser, combining pulsed laser heating with MHz x-ray diffraction. Here, we use this setup to determine liquidus temperatures under extreme conditions, based on the determination of time-resolved crystallization. The focus is on a Fe-Si-O ternary system, relevant for planetary cores. This time-resolved diagnostic is complemented by a finite-element model, reproducing temporal temperature profiles measured experimentally using streaked optical pyrometry. This model calculates the temperature and strain fields by including (i) pressure and temperature dependencies of material properties, and (ii) the heat-induced thermal stress, including feedback effect on material parameter variations. Making our model more realistic, these improvements are critical as they give 7000 K temperature differences compared to previous models. Laser intensities are determined by seeking minimal deviation between measured and modeled temperatures. Combining models and streak optical pyrometry data extends temperature determination below detection limit. The presented approach can be used to infer the liquidus temperature by the appearance of SiO 2 diffraction spots. In addition, temperatures obtained by the model agree with crystallization temperatures reported for Fe–Si alloys. Our model reproduces the planetary relevant experimental conditions, providing temperature, pressure, and volume conditions. Those predictions are then used to determine liquidus temperatures at experimental timescales where chemical migration is limited. This synergy of novel time-resolved experiments and finite-element modeling pushes further the interpretation capabilities in diamond anvil cell experiments. [ABSTRACT FROM AUTHOR]

Obtaining Heusler alloys at the nanoscale with good crystallographic features is appealing for a large range of technological applications, from biomedical to spintronics devices. In particular, Fe 2 CrAl as bulk is known to present magnetic properties that are strongly sensitive to chemical and physical constraints, such as structural disorder and chemical composition. We report a throughout structural, morphological, and magnetic characterization of Fe 2 CrAl Heusler nanoparticles obtained by pulsed laser deposition technique. The nanoparticles are composed of slightly off-stoichiometric grains with two distinct morphologies where the role of chemical disorder and inhomogeneity on the magnetic behavior was evaluated. Through DC magnetization measurements, a superparamagnetic behavior is observed and a Gilbert damping of 9 × 10 − 3 is acquired from broadband ferromagnetic resonance data, which is comparable with standard materials used for magnonics applications. We discuss the complex magnetostructural coupling that rises on the nanoparticle system, comparing these results with the stoichiometric Fe 2 CrAl bulk target behavior. [ABSTRACT FROM AUTHOR]

Defects in pulsed-laser deposition grown $\kappa{\hbox -}{\rm Ga}_2{\rm O}_3$ have been investigated using thermal admittance spectroscopy and secondary ion mass spectrometry (SIMS). A $\kappa {\hbox -}{\rm Ga}_2{\rm O}_3$ film was grown on either a tin-doped indium oxide or an aluminum-doped zinc oxide buffer layer on a sapphire substrate functioning as back contact layer in vertical diode structures. In both sample types, a distinct signature in the capacitance signal was observed in the temperature range of 150–260 K. The corresponding defect charge-state transition level, labeled $E_0$ , was found to exhibit an activation energy of 0.21 eV. Potential candidates for the $E_{0}$ level were investigated using a combination of SIMS and hybrid-functional calculations. SIMS revealed the main impurities in the sample to be tin, silicon, and iron. The hybrid-functional calculations predict the acceptor levels of substitutional iron to lie 0.7–1.2 eV below the conduction band minimum depending on Ga-site, making ${\rm Fe}_{{\rm Ga}}$ an unlikely candidate for the $E_0$ level. Furthermore, Si as well as Sn substituting on the sixfold coordinated Ga2 site and the fivefold coordinated Ga3 and Ga4 sites are all shallow donors in $\kappa$ - ${\rm Ga}_2{\rm O}_3$ , similar to that of $\beta$ - ${\rm Ga}_2{\rm O}_3$. Sn substituting on the fourfold Ga1 site is, however, predicted to have levels in the bandgap at 0.15 and 0.24 eV below the conduction band minimum, in accordance with the extracted activation energy for $E_{0}$. Thus, we tentatively assign ${\rm Sn}_{{\rm Ga}1}$ as the origin of the $E_0$ level. [ABSTRACT FROM AUTHOR]