The ultrafast laser-matter interaction is explored to induce new pioneering principles and technologies into the realms of fundamental science and industrial production.The local thermal melting and connection propert...The ultrafast laser-matter interaction is explored to induce new pioneering principles and technologies into the realms of fundamental science and industrial production.The local thermal melting and connection properties of the ultrafast laser welding technology offer a novel method for welding of diverse transparent materials,thus having wide range of potential applications in aerospace,opto-mechanical systems,sensors,microfluidic,optics,etc.In this comprehensive review,tuning the transient electron activation processes,high-rate laser energy deposition,and dynamic evolution of plasma morphology by the temporal/spatial shaping methods have been demonstrated to facilitate the transition from conventional homogeneous transparent material welding to the more intricate realm of transparent/metal heterogeneous material welding.The welding strength and stability are also improvable through the implementation of real-time,in-situ monitoring techniques and the prompt diagnosis of welding defects.The principles of ultrafast laser welding,bottleneck problems in the welding,novel welding methods,advances in welding performance,in-situ monitoring and diagnosis,and various applications are reviewed.Finally,we offer a forward-looking perspective on the fundamental challenges within the field of ultrafast laser welding and identify key areas for future research,underscoring the imperative need for ongoing innovation and exploration.展开更多
With the rapid advancement of terahertz technologies,electromagnetic interference(EMI)shielding materials are needed to ensure secure electromagnetic environments.Enormous efforts have been devoted to achieving highly...With the rapid advancement of terahertz technologies,electromagnetic interference(EMI)shielding materials are needed to ensure secure electromagnetic environments.Enormous efforts have been devoted to achieving highly efficient EMI shielding films by enhancing flexibility,lightweight,mechanical robustness,and high shielding efficiency.However,the consideration of the optical properties of these shielding materials is still in its infancy.By incorporating transparency,visual information from protected systems can be preserved for monitoring interior working conditions,and the optical imperceptibility allows nonoffensive and easy cover of shielding materials for both device and biology.There are many materials that can be applied to transparent EMI shields.In particular,two-dimensional transition metal carbide/nitrides(MXenes),possessing the advantages of superior conductivity,optical properties,favorable flexibility,and facile processibility,have become a great candidate.This work reviews the recent research on developing highly efficient and optically transparent EMI shields in a comprehensive way.Materials from MXenes,indium tin oxide,metal,carbon,and conductive polymers are covered,with a focus on the employment of MXene-based composites in transparent EMI shielding.The prospects and challenges for the future development of MXene-based transparent EMI shields are discussed.This work aims to promote the development of high-performance,optically transparent EMI shields for broader applications by leveraging MXenes.展开更多
We report an effective enhancement in light extraction of Ga N-based light-emitting diodes（LEDs） with an Al-doped Zn O（AZO） transparent conductive layer by incorporating a top regular textured SiO2 layer. The 2 in...We report an effective enhancement in light extraction of Ga N-based light-emitting diodes（LEDs） with an Al-doped Zn O（AZO） transparent conductive layer by incorporating a top regular textured SiO2 layer. The 2 inch transparent throughpore anodic aluminum oxide（AAO） membrane was fabricated and used as the etching mask. The periodic pore with a pitch of about 410 nm was successfully transferred to the surface of the SiO2 layer without any etching damages to the AZO layer and the electrodes. The light output power was enhanced by 19% at 20 m A and 56% at 100 m A compared to that of the planar LEDs without a patterned surface. This approach offers a technique to fabricate a low-cost and large-area regular pattern on the LED chip for achieving enhanced light extraction without an obvious increase of the forward voltage.展开更多
A kind of transparent plastic material has been prepared with bulk copolymer of MMA-MA containing MA 20 vol% as matrix modified by introducing EtOH during bulk copolymerization to increase the transparency and by copo...A kind of transparent plastic material has been prepared with bulk copolymer of MMA-MA containing MA 20 vol% as matrix modified by introducing EtOH during bulk copolymerization to increase the transparency and by copolymerizing together with metallic salts of MA forming ionomer polymer to improve the heat-tolerance and hardness. The effect of the contents of the additives on the heat stability, hardness and transparency of the copolymer has been studied. The optical homogeneity of the copolymer material has also been examined. It has been found that the specific property of transparent material of this kind may be obtained by controlling the amounts of EtOH and metallic salt of MA.展开更多
Three A-shaped nitropyrimidine derivatives with benzyl or furfuryl as bridge havebeen synthesized. They possess shorter absorption wavelengths (λ_(cut-off))<400 nm) andhigher βμ values (around 10^(-46) esu). The...Three A-shaped nitropyrimidine derivatives with benzyl or furfuryl as bridge havebeen synthesized. They possess shorter absorption wavelengths (λ_(cut-off))<400 nm) andhigher βμ values (around 10^(-46) esu). The second order nonlinear optical coefficient d_(33) ofpoled BNPMOPMDA/PMMA doped film is 1.2-2.0×10^(-9) esu obtained by in-situ SHGmeasurements. It can be expected that the chromophore-functionalized polymer containinghigher number density of synthesized chromophore as side chain will be the potential blue-light transparent frequency doubling materials.展开更多
Thermal stress-induced birefringence in borate glass which has been irradiated by 800-nm femtosecond laser pulses is observed under cross-polarized light. Due to the high temperature and pressure formed in the focal v...Thermal stress-induced birefringence in borate glass which has been irradiated by 800-nm femtosecond laser pulses is observed under cross-polarized light. Due to the high temperature and pressure formed in the focal volume, the material at the edge of the micro-modified region is compressed between the expanding region and the unheated one, then stress emerges. Raman spectroscopy is used to investigate the stress distribution in the micro-modified region and indicates the redistributions of density and refractive index by Raman peak shift. We suggest that this technique can develop waveguide polarizers and Fresnel zone plates in integrated optics.展开更多
We report on structural change in an Au^3＋-doped BK7 glass irradiated by an infrared femtosecond laser at 800 nm. A grating structure is inscribed in the glass sample. The glass sample is then annealed at various tem...We report on structural change in an Au^3＋-doped BK7 glass irradiated by an infrared femtosecond laser at 800 nm. A grating structure is inscribed in the glass sample. The glass sample is then annealed at various temperatures. Structural change of the grating is observed by an optical microscope. Absorption spectra indicate that colour centres are induced after the laser irradiation, and they decrease with increasing annealing temperature. Au nanoparticles are precipitated at high temperatures （≥ 600℃）. The mechanisms of the phenomena are discussed.展开更多
Multiple refocusing of a tightly focused femtosecond laser due to the dynamic transformation between self-focusing and self-defocusing is employed to provide a novel method to produce quasi-periodic voids in glass. It...Multiple refocusing of a tightly focused femtosecond laser due to the dynamic transformation between self-focusing and self-defocusing is employed to provide a novel method to produce quasi-periodic voids in glass. It is found that the diameter or the interval of the periodic voids increases with the increasing pulse energy of the laser. The detailed course for producing periodic voids is discussed by analysing the damaged track induced by the tightly focused femtosecond laser pulses. It is suggested that this periodic structure has potential applications in fabrication of three-dimensional optical devices.展开更多
A review is given in the paper for solidification researches with transparent model materials. The effective experimental me- thod was first proposed by Jackson and Hunt in 1965. The transparent model materials for so...A review is given in the paper for solidification researches with transparent model materials. The effective experimental me- thod was first proposed by Jackson and Hunt in 1965. The transparent model materials for solidification researches are a kind of non-faceted crystals known as ＂plastic crystals＂ or ＂globular molecules＂, which have very low entropy of melting as that of metals. According to Jackson＇s theory proposed in 1958, entropy of phase transformation will determine whether the phase interface morphology is smooth or rough in atomic scale, which will lead to faceted or nonfacted phase interface in mi- croscopic and macroscopic scales. Succinonitrile （SCN） and its alloys with water, ethanol, acetone, and NH4C1-H：O solution are most commonly used as transparent model materials for solidification researches of dendritic growth, anisotropy of solid-liquid interfacial energy, crystal nucleation, crystal grain formation, directional solidification, eutectic and peritectic so- lidification, solidification defects formation such as bubble, hot tearing, etc. Among these researches, the most impressive work was the critical test of dendritic growth theories with high purity succinonitrile by Glicksman et al., which gave positive answer to the Ivantsov＇s analysis and negative answer to the ad hoc condition of the maximum velocity hypothesis. The future researches with transparent model materials could be suggested in three aspects： 1） accurate measurement of material proper- ties and alloy phase diagrams in more plastic crystals, especially to find more transparent eutectic and peritectic alloys; 2） accurate measurement of the grain boundary groove shape to obtain precise data of the anisotropy parameters of the interfacial free energy in transparent model materials; 3） to get clear pictures of solidification processes with morphology details in a rela- tively large area, with continuous movement of liquid and particles, in order to give experimental support to numerical simula- tions aimming at accurate description of microstructure formation during solidification of multicomponent alloys under complex conditions of real casting and welding processes.展开更多
Thanks to their record high refractive index and giant optical anisotropy,van der Waals(vdW)materials have accelerated the development of nanophotonics.However,traditional high refractive index materials,such as titan...Thanks to their record high refractive index and giant optical anisotropy,van der Waals(vdW)materials have accelerated the development of nanophotonics.However,traditional high refractive index materials,such as titanium dioxide(TiO_(2)),still dominate in the most important visible range.This is due to the current lack of transparent vdW materials across the entire visible spectrum.In this context,we propose that germanium disulfide(GeS_(2))could offer a significant breakthrough.With its high refractive index,negligible losses,and biaxial optical anisotropy across the whole visible range,GeS_(2)has the potential to complement TiO2 and close the application gap of vdW materials in the visible spectrum.The addition of GeS_(2)could have a profound impact on the design of van der Waals nanophotonic circuits for any operation wavelength from ultraviolet to infrared,emphasizing the significance of the potential impact of GeS_(2)on the field of nanophotonics.展开更多
The ion substitution characteristics of Y3＋-doped （Tb0.sY0.2）3A15012 transparent ceramics synthesized by a solid-state reaction and vacuum sintering are investigated. The sample sintered at 1 680℃ exhibits the bes...The ion substitution characteristics of Y3＋-doped （Tb0.sY0.2）3A15012 transparent ceramics synthesized by a solid-state reaction and vacuum sintering are investigated. The sample sintered at 1 680℃ exhibits the best optical properties, yielding a transmittance 〉75% from 900 to 1 600 nm. The Verdet constant of this sample at 632.8 nm is -108.79 rad.T-l.m-1. X-ray diffraction （XRD） results show that all of the samples have a pure garnet crystal structure without secondary phases. The microstructure of the samples reveals homogeneous grain sizes that averages 〈10μm.展开更多
基金supports from National Key R&D Program of China(Grant No.2023YFB4605500)National Natural Science Foundation of China(Grant No.52105498)+3 种基金Natural Science Foundation of Hunan Province(Grant No.2022JJ40597)the Science and Technology Innovation Program of Hunan Province(Grant No.2022RC1132)State Key Laboratory of Precision Manufacturing for Extreme Service Performance(Grant No.ZZYJKT2023-08)support in analyzing the status of ultrafast laser welding applications,as well as the corresponding project support(Grant No.HKF202400595).
文摘The ultrafast laser-matter interaction is explored to induce new pioneering principles and technologies into the realms of fundamental science and industrial production.The local thermal melting and connection properties of the ultrafast laser welding technology offer a novel method for welding of diverse transparent materials,thus having wide range of potential applications in aerospace,opto-mechanical systems,sensors,microfluidic,optics,etc.In this comprehensive review,tuning the transient electron activation processes,high-rate laser energy deposition,and dynamic evolution of plasma morphology by the temporal/spatial shaping methods have been demonstrated to facilitate the transition from conventional homogeneous transparent material welding to the more intricate realm of transparent/metal heterogeneous material welding.The welding strength and stability are also improvable through the implementation of real-time,in-situ monitoring techniques and the prompt diagnosis of welding defects.The principles of ultrafast laser welding,bottleneck problems in the welding,novel welding methods,advances in welding performance,in-situ monitoring and diagnosis,and various applications are reviewed.Finally,we offer a forward-looking perspective on the fundamental challenges within the field of ultrafast laser welding and identify key areas for future research,underscoring the imperative need for ongoing innovation and exploration.
基金This work was supported by the National Key R&DProgram of China(No.2021YFB3502500)the NationalNatural Science Foundation of China(Nos.22205131,22375115)+6 种基金the Natural Science Foundation of ShandongProvince(Nos.2022HYYQ-014 ,ZR2016BM16)the New 20 Funded Programs for Universities of Jinan(2021GXRC036)Provincial Key Research and Develop-ment Program of Shandong(2021ZLGX01)the Disci-pline Construction Expenditure for Distinguished Young Scholars of Shandong University(31370089963141)Shenzhen Municipal Special Fund for Guiding LocalScientific and Technological Development(China,2021Szvup071)Qilu Young Scholar Program ofShandong University(No.31370082163127)The authorsacknowledge the assistance of the Shandong UniversityTesting and Manufacturing Center for Advanced Materi-als and the support of the Xiaomi Foundation/XiaomiYoung Talents Program.
文摘With the rapid advancement of terahertz technologies,electromagnetic interference(EMI)shielding materials are needed to ensure secure electromagnetic environments.Enormous efforts have been devoted to achieving highly efficient EMI shielding films by enhancing flexibility,lightweight,mechanical robustness,and high shielding efficiency.However,the consideration of the optical properties of these shielding materials is still in its infancy.By incorporating transparency,visual information from protected systems can be preserved for monitoring interior working conditions,and the optical imperceptibility allows nonoffensive and easy cover of shielding materials for both device and biology.There are many materials that can be applied to transparent EMI shields.In particular,two-dimensional transition metal carbide/nitrides(MXenes),possessing the advantages of superior conductivity,optical properties,favorable flexibility,and facile processibility,have become a great candidate.This work reviews the recent research on developing highly efficient and optically transparent EMI shields in a comprehensive way.Materials from MXenes,indium tin oxide,metal,carbon,and conductive polymers are covered,with a focus on the employment of MXene-based composites in transparent EMI shielding.The prospects and challenges for the future development of MXene-based transparent EMI shields are discussed.This work aims to promote the development of high-performance,optically transparent EMI shields for broader applications by leveraging MXenes.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61204049 and 51402366)Guangdong Natural Science Foundation,China(Grant No.S2012040007363)Foundation for Distinguished Young Talents in Higher Education of Guangdong,China(Grant Nos.2012LYM 0058 and2013LYM 0022)
文摘We report an effective enhancement in light extraction of Ga N-based light-emitting diodes（LEDs） with an Al-doped Zn O（AZO） transparent conductive layer by incorporating a top regular textured SiO2 layer. The 2 inch transparent throughpore anodic aluminum oxide（AAO） membrane was fabricated and used as the etching mask. The periodic pore with a pitch of about 410 nm was successfully transferred to the surface of the SiO2 layer without any etching damages to the AZO layer and the electrodes. The light output power was enhanced by 19% at 20 m A and 56% at 100 m A compared to that of the planar LEDs without a patterned surface. This approach offers a technique to fabricate a low-cost and large-area regular pattern on the LED chip for achieving enhanced light extraction without an obvious increase of the forward voltage.
基金Project supported by the National Natural Science Foundation of China
文摘A kind of transparent plastic material has been prepared with bulk copolymer of MMA-MA containing MA 20 vol% as matrix modified by introducing EtOH during bulk copolymerization to increase the transparency and by copolymerizing together with metallic salts of MA forming ionomer polymer to improve the heat-tolerance and hardness. The effect of the contents of the additives on the heat stability, hardness and transparency of the copolymer has been studied. The optical homogeneity of the copolymer material has also been examined. It has been found that the specific property of transparent material of this kind may be obtained by controlling the amounts of EtOH and metallic salt of MA.
基金This work was supported by the grant of theted National Natural Science Foundation of China and by the Chinese Academy of Sciences.
文摘Three A-shaped nitropyrimidine derivatives with benzyl or furfuryl as bridge havebeen synthesized. They possess shorter absorption wavelengths (λ_(cut-off))<400 nm) andhigher βμ values (around 10^(-46) esu). The second order nonlinear optical coefficient d_(33) ofpoled BNPMOPMDA/PMMA doped film is 1.2-2.0×10^(-9) esu obtained by in-situ SHGmeasurements. It can be expected that the chromophore-functionalized polymer containinghigher number density of synthesized chromophore as side chain will be the potential blue-light transparent frequency doubling materials.
基金Supported by the National Natural Science Foundation of China under Grant Nos 50125208 and 60377017, and the Shanghai Leading Academic Discipline Program.
文摘Thermal stress-induced birefringence in borate glass which has been irradiated by 800-nm femtosecond laser pulses is observed under cross-polarized light. Due to the high temperature and pressure formed in the focal volume, the material at the edge of the micro-modified region is compressed between the expanding region and the unheated one, then stress emerges. Raman spectroscopy is used to investigate the stress distribution in the micro-modified region and indicates the redistributions of density and refractive index by Raman peak shift. We suggest that this technique can develop waveguide polarizers and Fresnel zone plates in integrated optics.
基金Supported by the National Natural Science Foundation of China under Grant No 50672087, and the National Basic Research Programme of China under Grant No 2006CB806000b.
文摘We report on structural change in an Au^3＋-doped BK7 glass irradiated by an infrared femtosecond laser at 800 nm. A grating structure is inscribed in the glass sample. The glass sample is then annealed at various temperatures. Structural change of the grating is observed by an optical microscope. Absorption spectra indicate that colour centres are induced after the laser irradiation, and they decrease with increasing annealing temperature. Au nanoparticles are precipitated at high temperatures （≥ 600℃）. The mechanisms of the phenomena are discussed.
基金Supported by the National Basic Research Programme of China under Grant No 2006CB806000b, and the National Natural Science Foundation of China under Grant No 50672087, and the Shanghai Leading Academic Discipline Project under Grant No T0104.
文摘Multiple refocusing of a tightly focused femtosecond laser due to the dynamic transformation between self-focusing and self-defocusing is employed to provide a novel method to produce quasi-periodic voids in glass. It is found that the diameter or the interval of the periodic voids increases with the increasing pulse energy of the laser. The detailed course for producing periodic voids is discussed by analysing the damaged track induced by the tightly focused femtosecond laser pulses. It is suggested that this periodic structure has potential applications in fabrication of three-dimensional optical devices.
基金supported by the National Basic Research Program of China (Grant No. 2011CB610402)the Fund of the State Key Laboratory of Solidification Processing in NWPU (Grant No. 02-TZ-2008)
文摘A review is given in the paper for solidification researches with transparent model materials. The effective experimental me- thod was first proposed by Jackson and Hunt in 1965. The transparent model materials for solidification researches are a kind of non-faceted crystals known as ＂plastic crystals＂ or ＂globular molecules＂, which have very low entropy of melting as that of metals. According to Jackson＇s theory proposed in 1958, entropy of phase transformation will determine whether the phase interface morphology is smooth or rough in atomic scale, which will lead to faceted or nonfacted phase interface in mi- croscopic and macroscopic scales. Succinonitrile （SCN） and its alloys with water, ethanol, acetone, and NH4C1-H：O solution are most commonly used as transparent model materials for solidification researches of dendritic growth, anisotropy of solid-liquid interfacial energy, crystal nucleation, crystal grain formation, directional solidification, eutectic and peritectic so- lidification, solidification defects formation such as bubble, hot tearing, etc. Among these researches, the most impressive work was the critical test of dendritic growth theories with high purity succinonitrile by Glicksman et al., which gave positive answer to the Ivantsov＇s analysis and negative answer to the ad hoc condition of the maximum velocity hypothesis. The future researches with transparent model materials could be suggested in three aspects： 1） accurate measurement of material proper- ties and alloy phase diagrams in more plastic crystals, especially to find more transparent eutectic and peritectic alloys; 2） accurate measurement of the grain boundary groove shape to obtain precise data of the anisotropy parameters of the interfacial free energy in transparent model materials; 3） to get clear pictures of solidification processes with morphology details in a rela- tively large area, with continuous movement of liquid and particles, in order to give experimental support to numerical simula- tions aimming at accurate description of microstructure formation during solidification of multicomponent alloys under complex conditions of real casting and welding processes.
基金K.S.N.acknowledges support from the Ministry of Education,Singapore(Research Centre of Excellence award to the Institute for Functional Intelligent Materials,I-FIM,project No.EDUNC-33-18-279-V12)the National Research Foundation,Singapore under its AI Singapore Programme(AISG Award No:AISG3-RP-2022-028)the Royal Society(UK,grant number RSRP\R\190000).
文摘Thanks to their record high refractive index and giant optical anisotropy,van der Waals(vdW)materials have accelerated the development of nanophotonics.However,traditional high refractive index materials,such as titanium dioxide(TiO_(2)),still dominate in the most important visible range.This is due to the current lack of transparent vdW materials across the entire visible spectrum.In this context,we propose that germanium disulfide(GeS_(2))could offer a significant breakthrough.With its high refractive index,negligible losses,and biaxial optical anisotropy across the whole visible range,GeS_(2)has the potential to complement TiO2 and close the application gap of vdW materials in the visible spectrum.The addition of GeS_(2)could have a profound impact on the design of van der Waals nanophotonic circuits for any operation wavelength from ultraviolet to infrared,emphasizing the significance of the potential impact of GeS_(2)on the field of nanophotonics.
基金supported by the National Natural Science Foundation of China(Nos.51172254 and 51202269)the Science and Technology Commission of Shanghai Municipality(No.10JC1415700)
文摘The ion substitution characteristics of Y3＋-doped （Tb0.sY0.2）3A15012 transparent ceramics synthesized by a solid-state reaction and vacuum sintering are investigated. The sample sintered at 1 680℃ exhibits the best optical properties, yielding a transmittance 〉75% from 900 to 1 600 nm. The Verdet constant of this sample at 632.8 nm is -108.79 rad.T-l.m-1. X-ray diffraction （XRD） results show that all of the samples have a pure garnet crystal structure without secondary phases. The microstructure of the samples reveals homogeneous grain sizes that averages 〈10μm.
