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Femtosecond laser micro/nano processing:from fundamental to applications
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作者 Le Gao Qiming Zhang Min Gu 《International Journal of Extreme Manufacturing》 2025年第2期337-386,共50页
Able to precisely control and manipulate materials'states at micro/nano-scale level,femtosecond(fs)laser micro/nano processing technology has undergone tremendous development over the past three decades.Free-formi... Able to precisely control and manipulate materials'states at micro/nano-scale level,femtosecond(fs)laser micro/nano processing technology has undergone tremendous development over the past three decades.Free-forming three-dimensional(3D)microscale functional devices and inducing fascinating and unique physical or chemical phenomena have granted this technology powerful versatility that no other technology can match.As this technology advances rapidly in various fields of application,some key challenges have emerged and remain to be urgently addressed.This review firstly introduces the fundamental principles for understanding how fs laser pulses interact with materials and the associated unique phenomena in section 2.Then micro/nano-fabrication in transparent materials by fs laser processing is presented in section 3.Thereafter,several high efficiency/throughput fabrication methods as well as pulse-shaping techniques are listed in sections 4 and 5 reviews four-dimensional(4D)and nanoscale printing realized by fs laser processing technology.Special attention is paid to the heterogeneous integration(HI)of functional materials enabled by fs laser processing in section 6.Several intriguing examples of 3D functional micro-devices created by fs laser-based manufacturing methods such as microfluidics,lab-on-chip,micro-optics,micro-mechanics,micro-electronics,micro-bots and micro-biodevices are reviewed in section 7.Finally,a summary of the review and a perspective are proposed to explore the challenges and future opportunities for further betterment of fs laser micro/nano processing technology. 展开更多
关键词 femtosecond laser laser micro/nano processing laser fabrication direct laser writing 3D laser lithography
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CW laser damage of ceramics induced by air filament
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作者 Chuan Guo Kai Li +9 位作者 Zelin Liu Yuyang Chen Junyang Xu Zhou Li Wenda Cui Changqing Song Cong Wang Xianshi Jia Ji'an Duan Kai Han 《Opto-Electronic Advances》 2025年第7期23-35,共13页
Combined pulsed laser(CPL),introduced in 1975 for target damage,integrates different lasers to achieve high peak power and pulse energy.However,despite decades of research,CPL remains unused for long-range target dama... Combined pulsed laser(CPL),introduced in 1975 for target damage,integrates different lasers to achieve high peak power and pulse energy.However,despite decades of research,CPL remains unused for long-range target damage due to the challenge of maintaining high peak power density over long distances.We note that a potential solution lies in leveraging the air filament generated by femtosecond laser,which can transmit peak power densities higher than 1014 W/cm^(2)under the power clamping effect.To address this,a concept of a femtosecond laser induced air filament-CW CPL for surface damage of ceramics was introduced.We found no surface changes in ceramic targets when irradiated with a CW laser alone.By way of contrast,the target can be penetrated in a very short time(20 ms)with the assistance of the femtosecond laser induced air filament.In this context,we employ high-speed shadow imaging,cross-timescale simulation models and macro-microscopic characterization,to elucidate the CPL damage mechanism.The optimal CPL,combining a 1 mJ femtosecond laser and a 500 W CW laser,yields a damage rate of 1.51×10^(7)μm^(3)/J,representing an improvement of approximately 175%compared to single femtosecond laser ablation and around 59%enhancement compared to coating-assisted CW laser ablation.Furthermore,the efficacy of the proposed femtosecond-CW CPL method is demonstrated in causing penetration damage of ceramic/metal composite material or direct damage of sapphire,showcasing its versatility in damaging applications.Consequently,the femtosecond-CW CPL ablation method presented in this paper holds great promise as a new type of damage method for transparent hard and brittle materials. 展开更多
关键词 laser damage femtosecond laser CW laser combined pulse laser CERAMICS
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Diagnosis of focal spots at relativistic intensity utilizing coherent radiation from laser-driven flying electron sheets
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作者 Shirui Xu Zhuo Pan +22 位作者 Ying Gao Jiarui Zhao Shiyou Chen Zhusong Mei Xun Chen Ziyang Peng Xuan Liu Yulan Liang Tianqi Xu Tan Song Qingfan Wu Yujia Zhang Zhipeng Liu Zihao Zhang Haoran Chen Qihang Han Jundong Shen Chenghao Hua Kun Zhu Yanying Zhao Chen Lin Xueqing Yan Wenjun Ma 《Matter and Radiation at Extremes》 2025年第2期16-23,共8页
Experimental validation of laser intensity is particularly important for the study of fundamental physics at extremely high intensities.However,reliable diagnosis of the focal spot and peak intensity faces huge challe... Experimental validation of laser intensity is particularly important for the study of fundamental physics at extremely high intensities.However,reliable diagnosis of the focal spot and peak intensity faces huge challenges.In this work,we demonstrate for the firs time that the coherent radiation farfiel patterns from laser–foil interactions can serve as an in situ,real-time,and easy-to-implement diagnostic for an ultraintense laser focus.The laser-driven electron sheets,curved by the spatially varying laser fiel and leaving the targets at nearly the speed of light,produce doughnut-shaped patterns depending on the shapes of the focal spot and the absolute laser intensities.Assisted by particle-in-cell simulations,we can achieve measurements of the intensity and the focal spot,and provide immediate feedback to optimize the focal spots for extremely high intensity. 展开更多
关键词 diagnosis focal spot peak intensity laser foil interactions laser fi coherent radiation farfiel patterns laser driven electron sheets experimental validation laser intensity focal spot coherent radiation
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Integrated laser processing platform based on metasurface
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作者 Mingbo Pu 《Opto-Electronic Advances》 2025年第2期1-4,共4页
Laser processing technologies enable the precise fabrication of arbitrary structures and devices with broad applications in micro-optics,micro-mechanics,and biomedicine.However,its adoption is limited by the large siz... Laser processing technologies enable the precise fabrication of arbitrary structures and devices with broad applications in micro-optics,micro-mechanics,and biomedicine.However,its adoption is limited by the large size,complexity,high cost,and low flexibility of optical systems.Metasurfaces enable precise multidimensional control of light fields,aligning well with the development trend toward compact,high-performance optical systems.Here,we review several recent studies on the application of metasurfaces in laser processing technologies,including 3D nanolithography,direct laser writing,and laser cutting.Metasurfaces provide an integrated operational platform with exceptional performance,poised to disrupt conventional laser processing workflows.This combination presents significant cost efficiency and substantial development potential,with promising applications in areas such as imaging,optical storage,advanced sensing,and space on-orbit manufacturing. 展开更多
关键词 laser processing two-photon polymerization direct laser writing laser cutting metasurface
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GaN-based blue laser diodes with output power of 5 W and lifetime over 20000 h aged at 60℃
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作者 Lei Hu Siyi Huang +6 位作者 Zhi Liu Tengfeng Duan Si Wu Dan Wang Hui Yang Jun Wang Jianping Liu 《Journal of Semiconductors》 2025年第4期9-11,共3页
Stimulated emission and lasing of GaN-based laser diodes(LDs)were reported at 1995[1]and 1996[2],right after the breakthrough of p-type doping[3−5],material quality[6]and the invention of high-brightness GaN-based LED... Stimulated emission and lasing of GaN-based laser diodes(LDs)were reported at 1995[1]and 1996[2],right after the breakthrough of p-type doping[3−5],material quality[6]and the invention of high-brightness GaN-based LEDs[7,8].However,it took much longer time for GaN-based LDs to achieve high power,high wall plug efficiency,and long lifetime.Until 2019,Nichia reported blue LDs with these performances[9],which open wide applications with GaN-based blue LDs. 展开更多
关键词 Blue laser diodes P type doping LIFETIME Output power Stimulated emission GAN based laser diodes stimulated emission lasing laser diodes lds
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Design and start-to-end beam dynamics simulation of the first super-radiant THz free-electron laser source in Thailand
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作者 Natthawut Chaisueb Sakhorn Rimjaem 《Nuclear Science and Techniques》 2025年第7期222-235,共14页
A super-radiant terahertz free-electron laser(THz-FEL)light source was developed for the first time in Thailand and Southeast Asia at the PBP-CMU Electron Linac Laboratory(PCELL)of Chiang Mai University.This radiation... A super-radiant terahertz free-electron laser(THz-FEL)light source was developed for the first time in Thailand and Southeast Asia at the PBP-CMU Electron Linac Laboratory(PCELL)of Chiang Mai University.This radiation source requires relatively ultrashort electron bunches to produce intense coherent THz pulses.Three electron bunch compression processes are utilized in the PCELL accelerator system comprising pre-bunch compression in an alpha magnet,velocity bunching in a radio-frequency(RF)linear accelerator(linac),and magnetic bunch compression in a 180°acromat system.Electron bunch compression in the magnetic compressor system poses considerable challenges,which are addressed through the use of three quadrupole doublets.The strengths of the quadrupole fields significantly influence the rotation of the beam line longitudinal phase space distribution along the bunch compressor.Start-to-end beam dynamics simulations using the ASTRA code were performed to optimize the electron beam properties for generating super-radiant THz-FEL radiation.The operational parameters considered in the simulations comprise the alpha magnet gradient,linac RF phase,and quadrupole field strengths.The optimization results show that 10-16MeV femtosecond electron bunches with a low energy spread(~0.2%),small normalized emittance(~15πmm·mrad),and high peak current(165-247A)can be produced by the PCELL accelerator system at the optimal parameters.A THz-FEL with sub-microjoule pulse energies can thus be obtained at the optimized electron beam parameters.The physical and conceptual design of the THz-FEL beamline were completed based on the beam dynamics simulation results.The construction and installation of this beamline are currently underway and expected to be completed by mid-2024.The commissioning of the beamline will then commence. 展开更多
关键词 THz radiation THz free-electron laser Super-radiant free-electron laser Pre-bunched free-electron laser Beam dynamic simulation Femtosecond electron bunches
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Room-temperature electrically injected GaN-based photoniccrystal surface-emitting lasers
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作者 Tong Xu Meixin Feng +10 位作者 Xiujian Sun Rui Xi Xinchao Li Shuming Zhang Qian Sun Xiaoqi Yu Kanglin Xiong Hui Yang Xianfei Zhang Zhuangpeng Guo Peng Chen 《Journal of Semiconductors》 2025年第9期6-8,共3页
Photonic crystal surface emitting lasers(PCSELs)utilize the Bragg diffraction of two-dimensional photonic crystals to achieve a single-mode output with a high power and a small divergence angle,and has recently attrac... Photonic crystal surface emitting lasers(PCSELs)utilize the Bragg diffraction of two-dimensional photonic crystals to achieve a single-mode output with a high power and a small divergence angle,and has recently attracted much attention^([1−3]).In 2023,Kyoto University reported GaAs-based 945 nm PCSELs with a continuous-wave(CW)single-mode output power of exceeding 50 W,and a narrow beam divergence angle of 0.05°,demonstrating a brightness of 1 GW·cm^(−2)·sr^(−1),which rivals those of the existing bulky lasers^([4]). 展开更多
关键词 room temperature photonic crystal surface emitting lasers pcsels utilize GaN based electrically injected bragg diffraction bulky lasers pcsels photonic crystal surface emitting lasers
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Millisecond laser processing of sapphire assisted by femtosecond laser-induced air filament
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作者 YI Zhao-xi JIA Xian-shi +8 位作者 CHEN Yu-yang XU Jun-yang GUO Chuan LI Kai WANG Cong LI Zhou HAN Kai MA Zhuang DUAN Ji-an 《Journal of Central South University》 2025年第9期3272-3284,共13页
High-energy continuous wave(CW)lasers are mostly used in laser damage applications,but efficient laser ablation of transparent materials is challenging due to low optical absorption.Considering the potential of femtos... High-energy continuous wave(CW)lasers are mostly used in laser damage applications,but efficient laser ablation of transparent materials is challenging due to low optical absorption.Considering the potential of femtosecond(fs)laser-induced air filament for high-peak laser transmission over long distances,femtosecond(fs)laser-induced air filaments are combined with a millisecond(ms)laser to form an fs-ms CPL,enhancing the efficiency of sapphire ablation through synchronized spatial-temporal focusing.Experimental results show that ablation efficiency increases with the ms peak power and duty ratio.Excessive thermal stress leads to fragmentation of the sapphire when the ms duty ratio is over 30%at the peak power of 800 W,or when the peak power is over 500 W at a duty ratio of 100%.Also,the mechanism of high-efficiency damage is revealed through in-situ high-speed imaging.According to it,the ablation process went through 4 stages within 1.5 ms:defect-creating,melting and ablation,spattering,and fragmentation.Finally,the equivalent ablation efficiency of the fs-ms CPL is as high as 1.73×10^(7)μm^(3)/J,about 28 times higher compared to the fs laser only.The CPL damage method explored in this paper can provide theoretical guidance for efficient laser damage of transparent materials. 展开更多
关键词 femtosecond laser combined pulse laser laser damage SAPPHIRE
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Laser Cooling Alkaline-earth Atoms for Optical Clock in Chinese Space Station
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作者 Guodong Zhao Jian Xia +19 位作者 Yun Liu Yongzhuang Zhou Chihua Zhou Feng Guo Wenhai Wang Dejing He Min Feng Ting Liang Jie Ren Qinfang Xu Junwei Meng Feng Gao Yong Shen Xiaotong Lu Benquan Lu Yebing Wang Xiaohua Hu Wei Tan Hongxin Zou Hong Chang 《Chinese Physics Letters》 2025年第6期63-69,共7页
This study presents an achievement of laser cooling of alkaline-earth atoms in the Chinese Space Station’s strontium(Sr)atomic space optical clock.The system’s core components,physical unit,optical unit,and electric... This study presents an achievement of laser cooling of alkaline-earth atoms in the Chinese Space Station’s strontium(Sr)atomic space optical clock.The system’s core components,physical unit,optical unit,and electrical unit,have a total volume of 306 L and a total mass of 163.8 kg.These compact and robust units can overcome mechanical vibrations and temperature fluctuations during space launch.The laser sources of the optical unit are composed of diode lasers,and the injection locking of slave lasers is automatically performed by a program.In the experiment,a blue magneto-optical trap of cold atoms was achieved,with the atom numbers estimated to be approximately(1.50±0.13)×10^(6) for 87Sr and(8.00±0.56)×10^(6) for 88Sr.This work establishes a foundation for atomic confinement and high-precision interrogation in space-based optical clocks and expands the frontiers of cold atom physics in microgravity. 展开更多
关键词 STRONTIUM diode lasersand laser cooling optical clock slave lasers alkaline earth atoms Chinese space station injection locking
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Precise in-situ modulation of bandgap-controlled single-crystalline perovskite microlasers 被引量:1
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作者 Bingwang Yang Maosheng Liu +5 位作者 Sihao Xia Peng Wan Daning Shi Caixia Kan Xiaosheng Fang Mingming Jiang 《Journal of Materials Science & Technology》 2025年第11期27-36,共10页
Development of on-chip coherent light sources with desired single-mode operation and straightforward spectral tunability has attracted intense interest due to ever-increasing demand for photonic devices and optoelectr... Development of on-chip coherent light sources with desired single-mode operation and straightforward spectral tunability has attracted intense interest due to ever-increasing demand for photonic devices and optoelectronic integration,but still faces serious challenges.Herein,we propose a facile method to synthesize cesium lead halide(CsPbX3)microstructures with well-defined morphologies,sizes,and constituent element gradient.The scheme is conducted using a chemical vapor deposition(CVD),which is subsequently associated with annealing-assisted solid-solid anion exchange.For the plate-shaped structures,the controllability on the cross-sectional dimension enables to precisely modulate the lasing modes,thus achieving single-mode operation;while tuning the stoichiometric of the halogen anion components in the plate-shaped CsPbI_(x)Br_(3−x) alloy samples,the lasing wavelengths are straightforwardly varied to span the entire visible spectrum.By comparison,the experimental scheme on synthesizing alloyed CsPbI_(x)Br_(3−x) perovskites is conducted using an in-situ approach,thereby achieving precise modulation of bandgap-controlled microlasers by controlling the reaction time.Such laser properties like controllable microcavity modes and broad stoichiometry-dependent tunability of light-emitting/lasing colors,associated with the facile synthesizing method of monocrystalline CsPbI_(x)Br_(3−x) structures,make lead halide perovskites ideal materials for the development of wavelength-controlled microlasers toward practical photonic integration. 展开更多
关键词 MICROlaser Tunable lasing mode Annealing-assisted solid-solid anion exchange In-situ approach Wavelength-tunable laser PHOTOSTABILITY
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275 nm ultraviolet laser with 351 mW continuous-wave output in a Pr:YLF laser pumped by a blue laser diode at 444.2 nm
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作者 ZHENG Quan XIAO Hui-dong +6 位作者 CHEN Xi WANG Yan WANG Yu-ning LIU Hui-zhen TIAN Dong-he WANG Jin-yan YAO Yi 《中国光学(中英文)》 北大核心 2025年第2期376-381,共6页
This paper describes what is thought to be the first generation of a continuous wave deep ultraviolet laser at 275 nm by efficient frequency doubling of a blue-diode-pumped Pr:YLF laser at 550 nm.By employing a novel ... This paper describes what is thought to be the first generation of a continuous wave deep ultraviolet laser at 275 nm by efficient frequency doubling of a blue-diode-pumped Pr:YLF laser at 550 nm.By employing a novel fast-axis collimated blue semiconductor laser as the pump source,combined with a folded cavity and innovation coating technology,and utilizing a Brewster-cut BBO crystal for intracavity frequency doubling,TEM00 mode deep UV laser radiation at 275 nm with an output power of 351 mW is obtained.This marks the first report of achieving 275 nm laser generation based on Pr:LiYF4 to date. 展开更多
关键词 CW ultraviolet laser 275 nm laser Pr:YLF frequency doubling
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Laser hemorrhoidoplasty in focus:A modern alternative to conventional surgical techniques for symptomatic hemorrhoids
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作者 Alfadl Abdulfattah Fabricio Doin Paz de Oliveira 《World Journal of Surgical Procedures》 2025年第2期1-5,共5页
Hemorrhoidal disease is a prevalent anorectal condition causing significant morbidity,affecting approximately 4%of the general population with incidence increasing with age and sedentary lifestyle.While conventional e... Hemorrhoidal disease is a prevalent anorectal condition causing significant morbidity,affecting approximately 4%of the general population with incidence increasing with age and sedentary lifestyle.While conventional excisional hemorrhoidectomy techniques such as Milligan-Morgan and Ferguson remain standard for long-term efficacy,they are often associated with substantial postoperative pain and prolonged recovery.This narrative review evaluates the comparative clinical outcomes of laser hemorrhoidoplasty(LHP)versus conventional surgical interventions in the treatment of grade II and III symptomatic hemorrhoids.A comprehensive analysis of comparative studies,randomized controlled trials,and meta-analyses published between 2020 and 2025 was conducted,with primary outcomes including postoperative pain,recovery time,operative duration,complication rates,and recurrence.Key findings from studies by Maloku et al and Hassan et al.were analyzed to contextualize real-world LHP use.Across multiple high-quality studies,LHP was consistently associated with significantly lower postoperative pain scores,reduced analgesic requirements,and faster return to daily activities.Maloku et al demonstrated a shorter mean operative time(15.9 minutes)and reduced pain compared to open techniques(26.8 minutes;P<0.01).Hassan et al confirmed these benefits in a cohort of 40 patients treated under local anesthesia.Operative time was generally comparable or shorter,and vessel ligation was suggested as an adjunct to improve outcomes in select cases.Complication rates were low and similar between groups,with LHP demonstrating minimal risk for major complications such as anal stenosis or incontinence.However,recurrence rates were higher with LHP in some studies,particularly in grade III disease.LHP offers a minimally invasive,low-morbidity alternative to excisional hemorrhoidectomy for appropriately selected patients.Despite superior short-term recovery profiles,potential for higher recurrence underscores the importance of patient selection and long-term follow-up.The role of local anesthesia and adjunctive vessel ligation merits further prospective evaluation. 展开更多
关键词 laser hemorrhoidoplasty HEMORRHOIDECTOMY Minimally invasive surgery HEMORRHOIDS Postoperative pain RECURRENCE Diode laser
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Fabrication of high-quality surface microtextures on GaN by femtosecond laser direct writing
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作者 Rushuai Hua Zongwei Xu +3 位作者 Zhixiang Tao Bing Dong Hong Wang Long Yang 《Nanotechnology and Precision Engineering》 2025年第1期45-57,共13页
Gallium nitride(GaN),as a third-generation semiconductor,is highly attractive due to its exceptional physical and chemical properties.Laser direct writing offers an efficient method for the precise processing of hard ... Gallium nitride(GaN),as a third-generation semiconductor,is highly attractive due to its exceptional physical and chemical properties.Laser direct writing offers an efficient method for the precise processing of hard and brittle materials.In this work,various types of surface microtexture were processed on GaN epilayers using a femtosecond laser with a wavelength of 1030 nm.The effects of the laser energy,singlepulse interval,number of pulses,and number of scan passes on groove machining were investigated with a view to achieving high-quality micromachining.The depth,width,surface morphology,and roughness of the grooves were analyzed using scanning electron microscopy,laser scanning confocal microscopy,and atomic force microscopy.Damage and stress were characterized at the microscale using Raman spectroscopy.High-quality precision machining of different types of periodic surface microtexture at 40 mW laser power was achieved by controlling the process parameters and laser trajectory.Finally,an initial exploration was conducted to examine vector-light-based microand nanostructure processing.The findings demonstrate the potential of femtosecond lasers for efficient micromachining of hard and brittle materials without the creation of heat-affected zones or microcracks.The high-quality textured structures achieved through this processing technique have broad and promising applications in optoelectronic devices and tribology. 展开更多
关键词 Femtosecond laser laser processing Texture GAN RAMAN
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7-axis synchronization-integrated on-the-fly laser texturing system of freeform surface:design and development
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作者 Wenqi Ma Jinmiao Zhang +4 位作者 Liang Zhao Zhenjiang Hu Xuesen Zhao Tao Sun Junjie Zhang 《International Journal of Extreme Manufacturing》 2025年第1期435-451,共17页
While laser surface texturing(LST)is a promising manufacturing technique for surface functionalization,simultaneously realizing high precision and high efficiency in the LST of complex curved surface is challenging,du... While laser surface texturing(LST)is a promising manufacturing technique for surface functionalization,simultaneously realizing high precision and high efficiency in the LST of complex curved surface is challenging,due to continuously varied geometries of laser-matter incidence.In the present work,we propose a novel manufacturing system of 7-axis on-the-fly LST for complex curved surface,based on the integrated synchronization of 5-axis linkage motion platform with 2-axis galvanometer.Specifically,the algorithm for decomposing spatial texture trajectory on curved surface into low-frequency and high-frequency parts is established,based on which the kinematic model of synchronized 7-axis system is developed to derive the motion of each axis in both 5-axis linkage motion platform and 2-axis galvanometer simultaneously.Subsequently,the synchronized 7-axis LST system is experimentally realized,including the setup of mechanical stages integrated with optical path,the configuration of numerical control unit,and the development of processing software.Finally,case study of 7-axis on-the-fly LST of freeform aluminum surface is performed,and the advantages in terms of processing efficiency and texturing accuracy over 5-axis linkage LST are demonstrated.The correlation of reduced following errors between mechanical stages with the promoted performance of curved surface texturing by the 7-axis on-the-fly LST is further analyzed.Current work provides a feasible solution for establishing the manufacturing system for high performance LST of complex curved surface. 展开更多
关键词 laser surface texturing freeform surface multi-axis synchronization multi-axis linkage motion following error laser micromachining system
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Physics-Informed Gaussian Process Regression with Bayesian Optimization for Laser Welding Quality Control in Coaxial Laser Diodes
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作者 Ziyang Wang Lian Duan +2 位作者 Lei Kuang Haibo Zhou Ji’an Duan 《Computers, Materials & Continua》 2025年第8期2587-2604,共18页
The packaging quality of coaxial laser diodes(CLDs)plays a pivotal role in determining their optical performance and long-term reliability.As the core packaging process,high-precision laser welding requires precise co... The packaging quality of coaxial laser diodes(CLDs)plays a pivotal role in determining their optical performance and long-term reliability.As the core packaging process,high-precision laser welding requires precise control of process parameters to suppress optical power loss.However,the complex nonlinear relationship between welding parameters and optical power loss renders traditional trial-and-error methods inefficient and imprecise.To address this challenge,a physics-informed(PI)and data-driven collaboration approach for welding parameter optimization is proposed.First,thermal-fluid-solid coupling finite element method(FEM)was employed to quantify the sensitivity of welding parameters to physical characteristics,including residual stress.This analysis facilitated the identification of critical factors contributing to optical power loss.Subsequently,a Gaussian process regression(GPR)model incorporating finite element simulation prior knowledge was constructed based on the selected features.By introducing physics-informed kernel(PIK)functions,stress distribution patterns were embedded into the prediction model,achieving high-precision optical power loss prediction.Finally,a Bayesian optimization(BO)algorithm with an adaptive sampling strategy was implemented for efficient parameter space exploration.Experimental results demonstrate that the proposedmethod effectively establishes explicit physical correlations between welding parameters and optical power loss.The optimized welding parameters reduced optical power loss by 34.1%,providing theoretical guidance and technical support for reliable CLD packaging. 展开更多
关键词 Coaxial laser diodes laser welding physics-informed Gaussian process regression Bayesian optimization
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Comparison of clinical effectiveness and safety of 272μm and 365μm holmium lasers in retrograde intrarenal surgery
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作者 Demirhan Orsan Demir Yusuf Gokkurt +4 位作者 Salih Bürlükkara Turgay Kacan Ali Kaan Yıldız Ufuk Bozkurt Tolga Karakan 《The Canadian Journal of Urology》 2025年第2期111-118,共8页
Introduction:Surgeons typically prefer 270μm and 272μm laser probes in retrograde intrarenal surgery(RIRS)due to the reduced deflection capacity of flexible ureterorenoscopes when using larger probe diameters.This s... Introduction:Surgeons typically prefer 270μm and 272μm laser probes in retrograde intrarenal surgery(RIRS)due to the reduced deflection capacity of flexible ureterorenoscopes when using larger probe diameters.This study aims to investigate the effects of 272 and 365μm holmium laser probes on operative time,clinical efficacy,and complication rates in RIRS.Materials and Methods:A total of 285 patients with proximal ureteral or kidney stones who met the inclusion criteria were enrolled in the study.Patients were divided into two groups based on laser probe thickness:272μm and 365μm.Stone-free rates,operative time,and complication rates were compared between the groups.Factors affecting stone-free rates were analyzed using multivariate logistic regression analysis.Results:Patient and stone characteristics were similar between the two groups.No significant differences were found in stone-free or complication rates.However,operative time was significantly shorter in the 365μm probe group.In univariate analysis,risk factors for postoperative residual stones included multi-calyceal stones,lower pole stones,high Hounsfield unit(HU)values on noncontrast computed tomography,and larger stone size.In multivariate analysis,independent prognostic factors for residual stones were identified as multi-calycal stones,lower pole stones,and high HU values.Conclusion:Compared to 272μm laser probes,operative time was shorter in surgeries performed with 365μm laser probes.The 365μm holmium laser can be effectively and safely used in the treatment of proximal ureteral and renal stones,demonstrating high clinical efficacy and safety. 展开更多
关键词 272μm laser 365μm laser EFFECTIVENESS RIRS SAFETY
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Influence of laser shock peening on microstructure and high-temperature oxidation resistance of Ti45Al8Nb alloy fabricated via laser melting deposition
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作者 Lu-lu JIANG Liang LAN +6 位作者 Cheng-yan BAI Ru-yi XIN Shuang GAO Hao-yu WANG Bo HE Chao-yue CHEN Guo-xin LU 《Transactions of Nonferrous Metals Society of China》 2025年第1期157-168,共12页
Laser shock peening(LSP)was used to enhance the high-temperature oxidation resistance of laser melting deposited Ti45Al8Nb alloy.The microstructure and high-temperature oxidation behavior of the as-deposited Ti45Al8Nb... Laser shock peening(LSP)was used to enhance the high-temperature oxidation resistance of laser melting deposited Ti45Al8Nb alloy.The microstructure and high-temperature oxidation behavior of the as-deposited Ti45Al8Nb alloy before and after LSP were investigated by scanning electron microscopy,X-ray diffraction,and electron backscatter diffraction.The results indicated that the rate of mass gain in the as-deposited sample after LSP exhibited a decrease when exposed to an oxidation temperature of 900℃,implying that LSP-treated samples exhibited superior oxidation resistance at high temperatures.A gradient structure with a fine-grain layer,a deformed-grain layer,and a coarse-grain layer was formed in the LSP-treated sample,which facilitated the diffusion of the Al atom during oxidation,leading to the formation of a dense Al_(2)O_(3)layer on the surface.The mechanism of improvement in the oxidation resistance of the as-deposited Ti45Al8Nb alloy via LSP was discussed. 展开更多
关键词 TiAl alloy laser melting deposition laser shock peening additive manufacturing oxidation resistance
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Effect of femtosecond laser surface texturing on adhesion performance and fracture mechanism of thermal barrier coatings
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作者 Yue HU Shaojian WANG +2 位作者 Ruisong JIANG Chongxiang HUANG Chaolang CHEN 《Chinese Journal of Aeronautics》 2025年第9期489-504,共16页
To enhance the adhesion of ceramic coatings in turbine blade Thermal Barrier Coatings(TBCs)systems,Laser Surface Texturing(LST)was employed to create microstructures on the metal bond coat.The bonding conditions and f... To enhance the adhesion of ceramic coatings in turbine blade Thermal Barrier Coatings(TBCs)systems,Laser Surface Texturing(LST)was employed to create microstructures on the metal bond coat.The bonding conditions and failure mechanisms of the ceramic coatings within these microstructures were thoroughly investigated.Femtosecond laser technology was used to fabricate three types of high-quality microstructure grooves:linear,sine wave,and grid patterns.These grooves exhibit uniform morphology,well-defined edges,and smooth inner walls.After ceramic coating deposition,columnar crystal structures grew perpendicularly along the groove walls,completely filling the microstructures and forming an arched support structure that significantly enhances mechanical interlocking and adhesion.Among the different microstructures,grid patterns demonstrated the best adhesion performance.In scratch tests,grid-patterned microstructures exhibited only localized small block spalling under high load conditions,avoiding large-scale delamination.This superior performance is attributed to the ability of grid pattern to effectively distribute stress in multiple directions and prevent crack propagation.By reducing stress concentration and enhancing mechanical interlocking points,grid-patterned microstructures also showed excellent resistance to spallation during thermal cycling,markedly improving the thermal resistance and adhesion of coating. 展开更多
关键词 ADHESION Femtosecond lasers laser materials processing Thermal barrier coatings Thermal cycling
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Fabrication of Porous SiC Coatings on Quartz Substrates by Laser Chemical Vapor Deposition
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作者 YANG Meijun CHEN Rui +4 位作者 XU Qingfang GUO Bingjian LIU Kai TU Rong ZHANG Song 《Journal of Wuhan University of Technology(Materials Science)》 2025年第2期330-337,共8页
Laser etching and laser chemical vapor deposition(LCVD)techniques were proposed for the rapid preparation of high-purity,strongly bonded SiC porous micro-nano-coatings on quartz substrates.The laser serves as an exter... Laser etching and laser chemical vapor deposition(LCVD)techniques were proposed for the rapid preparation of high-purity,strongly bonded SiC porous micro-nano-coatings on quartz substrates.The laser serves as an external driving force for the vertical growth of SiC whiskers,facilitating the formation of a porous nanostructure that resembles coral models found in the macroscopic biological world.The porous nanostructures are beneficial for reducing thermal expansion mismatch and relieving residual stress.It is capable of eliminating the cracks on the surface of SiC coatings as well as enhancing the bonding of SiC coatings with quartz substrates to avoid coating detachment. 展开更多
关键词 laser etching laser CVD quartz substrate SiC coating
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Fluid Dynamics Research on Erbium Laser-Assisted Chemical Preparation for Root Canal Therapy:A Review
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作者 Kedi Jihu Xinyu He Jizhi Zhao 《Journal of Clinical and Nursing Research》 2025年第4期43-49,共7页
Microbial infection is a principal etiological factor in pulp and periapical diseases,necessitating effective root canal therapy(RCT)for thorough decontamination of the root canal system.However,conventional mechanica... Microbial infection is a principal etiological factor in pulp and periapical diseases,necessitating effective root canal therapy(RCT)for thorough decontamination of the root canal system.However,conventional mechanical and chemical preparation methods remain inadequate,often leaving significant portions of the canal uncleaned and contributing to persistent infection.The advent of erbium laser-assisted chemical preparation has demonstrated significant potential in enhancing root canal disinfection through advanced fluid dynamics mechanisms,particularly cavitation and photoacoustic streaming.This review explores the fundamental principles governing fluid dynamics in erbium laser-assisted irrigation,with a focus on primary and secondary cavitation effects.The interaction between erbium laser energy and water generates vapor bubbles that induce dynamic fluid movement,enhancing the penetration and distribution of irrigants deep within the root canal system.Key factors influencing fluid dynamics intensity,including laser parameters,working tip design,and water medium confinement,are critically analyzed.Furthermore,recent advancements such as Photon-Initiated Photoacoustic Streaming(PIPS),Photoacoustic Synchronized Transients(PHAST),and Shock Wave Enhanced Emission Photoacoustic Streaming(SWEEPS)are reviewed in the context of their ability to improve fluid motion and irrigation efficacy.While these laser-assisted techniques offer promising improvements over traditional methods,challenges remain in optimizing energy parameters and mitigating the constraints imposed by confined root canal environments.Future research should focus on refining fluid dynamics models and conducting clinical studies to validate the efficacy of these innovations.This review aims to provide a comprehensive overview of current developments in fluid dynamics research related to erbium laser-assisted chemical preparation,offering insights into its potential as an advanced modality for root canal disinfection. 展开更多
关键词 Root canal therapy laser adjunctive therapy Erbium laser Fluid dynamics Infection control
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