Numerical Simulation of Thermal Fields and Microstructure Evolution in SLM of FeCrNiAlTi Alloy.

Fabricating eutectic high-entropy alloys (EHEAs) via selective laser melting (SLM) presents significant potential for advanced structural applications. This study explores the microstructural evolution of FeCrNiAlTi EHEAs fabricated by SLM under varying laser powers. Electron backscatter diffraction (EBSD) analysis revealed that samples fabricated at 200 W exhibited approximately 70% face-centered-cubic (FCC) and 30% body-centered-cubic (BCC) phases.

Efficient and anti-interference plastic classification method suitable for one-shot learning based on laser induced breakdown spectroscopy.

Efficient recycling of plastics is critical for environmental sustainability. In this work, an efficient and anti-interference method for plastic classification based on one-shot learning and laser-induced breakdown spectroscopy (LIBS) was proposed. A residual neural network model with full-spectrum training (ResNet-FST) was developed based on convolutional neural networks, achieving an accuracy of 99.

Remote and in-situ monitoring of plasmon-induced catalysis reaction by fiber SERS probes.

Monitoring chemical reaction processes is of great significance in the study of the reaction mechanisms, and the optimization or control of reaction conditions. In this work, we demonstrate a novel monitoring method of chemical reactions using fiber SERS probes. The high-performance fiber SERS probes are prepared by the laser-induced evaporation self-assembly method (LIESAM), where lots of Au-nanorod clusters are deposited on the fiber facet for providing large SERS enhancement factor and good hot electron catalytic property.

Stable quantum droplets with high-order vorticity in zero-order Bessel lattice.

A theoretical framework is presented to investigate the stability of novel two-dimensional quantum droplets within zeroth-order Bessel lattices. The evolution of quantum droplets is studied by the Gross-Pitaevskii equations with Lee-Huang-Yang corrections. The circular groove structure inherent in the zeroth-order Bessel lattice potential facilitates the formation of distinct configurations, including stable zero-vorticity annular quantum droplets and annular quantum droplets featuring embedded vorticity.

Effect of Energy Density on Mechanical Properties of NiTiCu Shape Memory Alloys Prepared by SLM.

In the Ni-Ti shape memory alloy system, Cu elements are used to replace Ni elements. A NiTiCu alloy with a molar ratio of 45:50:5 was prepared using laser selective melting technology. The density, composition, microstructure, and mechanical properties of the NiTiCu alloy were investigated.

Accurate two-dimensional simulation model and experimental demonstration in ultraviolet picosecond laser scribing ablation.

Laser patterning of copper thin films is essential for the electronics manufacturing industry. In this work, to efficiently and accurately describe the physics process of UV-ps laser ablating copper thin film, a two-temperature model (TTM) consisting of the electron-lattice system and phase explosion mechanism was proposed. The process of electron heating and electron-lattice heat transfer in single pulse ablation were revealed.

Nested hollow-core anti-resonant fiber with elliptical cladding for 2 µm laser transmission.

In this work, a nested hollow-core anti-resonant fiber (HC-ARF) with an elliptical cladding for high-power lasers for 2 µm laser transmission was proposed and theoretically investigated. The dual-layer elliptical tubes nested within the fiber enable the low-loss single-mode transmission. The finite element method (FEM) was employed to analyze and optimize the structure of fiber, with a total loss of less than 5 × 10dB/m across the wavelength range of 1920nm to 2040nm.

Construction of LaSrNiO/g-CN type-Z heterojunctions with enhanced visible-light photocatalytic degradation of organic pollutants.

Lanthanum nickelate (LaNiO), known for its high visible-light absorption, is a promising photocatalyst for water purification. However, the low conduction band position and high photogenerated carrier complexation rate of pure LaNiO limit its photocatalytic activity. To address this issue, we investigated the synergistic effects of doping and constructing heterojunctions.

Effects of Heat Treatment on the Microstructure and Mechanical Properties of a Dual-Phase High-Entropy Alloy Fabricated via Laser Beam Power Bed Fusion.

To enhance the applicability of dual-phase high-entropy alloys (HEAs) like Fe32Cr33Ni29Al3Ti3, fabricated via laser beam power bed fusion (LB-PBF), a focus on improving their mechanical properties is essential. As part of this effort, heat treatment was explored. This study compares the microstructure and mechanical properties of the as-printed sample with those cooled in water after undergoing heat treatment at temperatures ranging from 1000 to 1200 °C for 1 h.

Generation of sub-100 fs pulses from a SESAM-NPE hybrid mode-locked Yb-doped fiber laser at a fundamental repetition rate of 1.15 GHz.

Supercontinuum generation via direct pumping of unamplified high-repetition-rate, sub-100 fs pulses with a pulse energy lower than 50 pJ is superior in noise performance and features a high acquisition speed. We demonstrate a novel, to the best of our knowledge, gigahertz-repetition-rate, mode-locked Yb-doped fiber laser, where the hybrid mode-locking approach is employed. The laser has a low initiating threshold of 300 mW and a broad mode-locking range of 600 mW (300-900 mW) in terms of pump power.

GHz-repetition-rate fundamentally mode-locked, isolator-free ring cavity Yb-doped fiber lasers with SESAM mode-locking.

A novel fundamentally mode-locked, GHz-repetition-rate ring cavity Yb-doped femtosecond fiber laser is demonstrated, which utilizes polarization-maintaining gain fiber and is enable by SESAM mode-locking. Thanks to the isolator-free structure, the ring cavity laser is operated bidirectionally and the two polarization-multiplexed output pulse trains are demonstrated synchronous. As a result, tunable waveforms one of which is with reduced pedestal and shorter pulse width in comparison with each individual, are generated by combination of the two orthogonal-polarized output pulses.

A method to classify bone marrow cells with rejected option.

Bone marrow cell morphology has always been an important tool for the diagnosis of blood diseases. Still, it requires years of experience from a suitable person. Furthermore, the outcomes of their recognition are subjective and there is no objective quantitative standard.

Analytical method for designing tunable terahertz absorbers with the desired frequency and bandwidth.

We present a novel and effective approach for designing and analyzing graphene metasurface-based terahertz absorbers with the desired central frequency and fractional bandwidth. Narrowband and broadband absorbers are designed using the same configuration with a single-layer of graphene ribbons deposited on a metal-backed dielectric film. An analytical circuit model derived for the graphene array applies the impedance matching concept to realize the desired terahertz absorber.

Accuracy improvement in plastics classification by laser-induced breakdown spectroscopy based on a residual network.

The whole ecosystem is suffering from serious plastic pollution. Automatic and accurate classification is an essential process in plastic effective recycle. In this work, we proposed an accurate approach for plastics classification using a residual network based on laser-induced breakdown spectroscopy (LIBS).

Graphene metalens with dynamic focusing and plane focusing in the terahertz range.

We theoretically propose a high-efficiency tunable metalens based on an ellipse-shaped perforated graphene metasurface. By optimizing the axial length ratio of the elliptical aperture, we find the elliptical aperture with high reflectivity over a broad band by means of observing the reflectivity at different frequencies. Then, varying the orientation of the elliptical aperture from 0° to 180°, the reflected wave can generate a continuous 2 range phase shift while keeping its amplitude high, which is necessary to achieve focusing.

Processing Technologies and Properties of Cu-10Sn Formed by Selective Laser Melting Combined with Heat Treatment.

The selective laser melting (SLM) process of the Cu-10Sn alloy and effects of heat treatment were examined in this study. The Taguchi test and Box-Behnken design were performed to determine the laser power (LP), scanning speed (SS), and hatch space (HS). The best process parameters were selected using the highest density: the optimum HS was 160 μm; SS was 278 mm s; LP was 192 W; and density reached 98.

Design of Dual-Band Terahertz Perfect Metamaterial Absorber Based on Circuit Theory.

We present a novel strategy for designing a dual-band absorber based on graphene metasurface for terahertz frequencies. The absorber consists of a two-dimensional array of patches deposited on a metal-backed dielectric layer. Using an analytical circuit model, we obtain closed-form relatinos for the geometrical parameters of the absorber and the properties of the applied materials to achieve the dual-band absorber.

All-polarization-maintaining, all-normal-dispersion mode-locked fiber laser with spectral filtering in a nonlinear optical loop mirror.

The spectral filtering effect is essential to dissipative dynamics in an all-normal-dispersion (ANDi) mode-locked fiber laser. In this study, we numerically and experimentally demonstrate the spectral filtering process of a nonlinear optical loop mirror (NOLM). Taking advantage of the 40/60 NOLM's spectral filtering ability, we designed a novel all-polarization-maintaining ANDi mode-locked fiber laser without using a separate spectral filter.

Investigation of the reaction mechanism and optical transparency in nanosecond laser welding of glasses assisted with titanium film.

The welding of glasses is widely used in many fields, such as optics, microfluidics, and microelectromechanical systems. In this paper, two pieces of 1 mm soda lime glass substrates were welded using a 1064 nm nanosecond laser assisted with a 14 nm titanium-coated thin film coating. Results show that after the laser irradiation, the welded area becomes highly transparent much like uncoated glass.

A Simple and Efficient Method for Designing Broadband Terahertz Absorber Based on Singular Graphene Metasurface.

In this paper, we propose a simple and efficient method for designing a broadband terahertz (THz) absorber based on singular graphene patches metasurface and metal-backed dielectric layer. An accurate circuit model of graphene patches is used for obtaining analytical expressions for the input impedance of the proposed absorber. The input impedance is designed to be closely matched to the free space in a wide frequency range.

Experimental investigation of laser-induced breakdown spectroscopy assisted with laser-induced fluorescence for trace aluminum detection in steatite ceramics.

Laser-induced breakdown spectroscopy (LIBS) assisted with laser-induced fluorescence (LIF) was introduced to detect trace aluminum in steatite ceramics in this work. The mechanism and transition process of laser-induced aluminum atomic fluorescence in laser-induced plasma was described and discussed. Selective enhancement of LIF and temporal synchronicity between radiation laser and fluorescence were studied.

Sensitive determination of silicon contents in low-alloy steels using micro laser-induced breakdown spectroscopy assisted with laser-induced fluorescence.

Silicon element plays an important role in strength and hardness improvement in steels, but is harmful for ductility, tenacity, and anti-corrosion. Therefore, silicon content should be fast determined in steel manufacture to keep silicon in moderation. In this work, micro laser-induced breakdown spectroscopy assisted with laser-induced fluorescence (μLIBS-LIF) was proposed to sensitively determine silicon in low-alloy steels.

870 fs, 448 kHz pulses from an all-polarization-maintaining Yb-doped fiber laser with a nonlinear amplifying loop mirror.

We demonstrate a mode-locked long all-polarization-maintaining fiber laser with a nonlinear amplifying loop mirror. The fiber oscillator directly delivers 221 ps chirped pulses at the repetition rate of 448 kHz. The pulses can be further amplified up to 134 nJ and compressed down to 870 fs by a grating pair.