Blueberry(Vaccinium ashei)is highly characterized by its nutritional value,with an extremely high anthocyanin content,and rabbiteye blueberry is widely grown across China.However,molecular regulatory mechanisms underl...Blueberry(Vaccinium ashei)is highly characterized by its nutritional value,with an extremely high anthocyanin content,and rabbiteye blueberry is widely grown across China.However,molecular regulatory mechanisms underlying the high anthocyanin accumulation during the fruit development and colouration of rabbiteye blueberry fruit,have not yet been fully clarified so far.The fruit anthocyanin content of rabbiteye blueberry in the karstic area of Guizhou Province,China,is much higher compared to that in other regions,and the fruit colour is highly affected by anthocyanin accumulation.Currently,the untargeted metabolomics and HPLC assays have been carried out using rabbiteye blueberry fruit at various stages,and it was investigated that cyanidin(Cy)and pelargonidin(Pg)reached their peaks at the red fruit(RF)stage,whereas delphinidin(Dp),petudinin(Pt),malvidin(Mv),and peonidin(Pn)got their ceilings at the mature fruit(MF)stage.Transcriptome and co-expression network analyses showed that 27 differentially expressed genes(DEGs)were associated with anthocyanin content,among which VdMYB56,belonging to the R2R3-MYB family,was markedly up-regulated during the development and colouration of fruit,and was significantly higher in the skin than in the pulp.Furthermore,VdMYB56-overexpressing tomato fruits demonstrated a substantial elevation in anthocyanin content on the 35th day after flowering(DAF).It was worth noting that VdMYB56 could directly bind to the promoter of Vd3GT to enhance its expression,thereby further strengthening the anthocyanin accumulation.Meantime,multiple assays verified that VdMYB69,an R2R3-MYB member,might interact with VdMYB56,leading to the promotion of VdMYB56 expression.Conclusively,the VdMYB56-VdMYB69 module is a positive regulator of anthocyanin biosynthesis in rabbiteye blueberry,which may provide new insights into high-anthocyanin breeding,particularly for the southern karstic regions.展开更多
Compressing all the energy of a laser pulse into a spatiotemporal focal cube edged by the laser center wavelength will realize the highest intensity of an ultra-intense ultrashort laser,which is called theλ^(3) regim...Compressing all the energy of a laser pulse into a spatiotemporal focal cube edged by the laser center wavelength will realize the highest intensity of an ultra-intense ultrashort laser,which is called theλ^(3) regime or theλ^(3) laser.Herein,we introduced a rotational hyperbolic mirror—an important rotational conic section mirror with two foci—that is used as a secondary focusing mirror after a rotational parabolic mirror to reduce the focal spot size from several wavelengths to a single wavelength by significantly increasing the focusing angular aperture.Compared with the rotational ellipsoidal mirror,the first focal spot with a high intensity,as well as some unwanted strong-field effects,is avoided.The optimal focusing condition of this method is presented and the enhanced tight focusing for a femtosecond petawatt laser and theλ3 laser is numerically simulated,which can enhance the focused intensities of ultra-intense ultrashort lasers for laser physics.展开更多
After reaching a world record of 10 PW,the peak power development of the titanium-sapphire(Ti:sapphire)PW ultraintense lasers has hit a bottleneck,and it seems to be difficult to continue increasing due to the difficu...After reaching a world record of 10 PW,the peak power development of the titanium-sapphire(Ti:sapphire)PW ultraintense lasers has hit a bottleneck,and it seems to be difficult to continue increasing due to the difficulty of manufacturing larger Ti:sapphire crystals and the limitation of parasitic lasing that can consume stored pump energy.Unlike coherent beam combining,coherent Ti:sapphire tiling is a viable solution for expanding Ti:sapphire crystal sizes,truncating transverse amplified spontaneous emission,suppressing parasitic lasing,and,importantly,not requiring complex space-time tiling control.A theoretical analysis of the above features and an experimental demonstration of high-quality laser amplification are reported.The results show that the addition of a 2×2 tiled Ti:sapphire amplifier to today’s 10 PW ultraintense laser is a viable technique to break the 10 PW limit and directly increase the highest peak power recorded by a factor of 4,further approaching the exawatt class.展开更多
Lead halide hybrid perovskites(LHP)have emerged as one of the most promising photovoltaic materials for their remarkable solar energy conversion ability.The transportation of the photoinduced carriers in LHP could scr...Lead halide hybrid perovskites(LHP)have emerged as one of the most promising photovoltaic materials for their remarkable solar energy conversion ability.The transportation of the photoinduced carriers in LHP could screen the defect recombination with the help of the large polaron formation.However,the physical insight of the relationship between the superior optical-electronic performance of perovskite and its polaron dynamics related to the electron-lattice strong coupling induced by the substitution engineering is still lack of investigation.Here,the bandgap modulated thin films ofα-FAPbI_(3)with different element substitution is investigated by the time resolved Terahertz spectroscopy.We find the polaron recombination dynamics could be prolonged in LHP with a relatively smaller bandgap,even though the formation of polaron will not be affected apparently.Intuitively,the large polaron mobility in(FAPb I_(3))0.95(MAPbI_(3))0.05thin film is~30%larger than that in(FAPb I_(3))0.85(MAPbBr_(3))0.15.The larger mobility in(FAPb I_(3))0.95(MAPb I_(3))0.05could be assigned to the slowing down of the carrier scattering time.Therefore,the physical origin of the higher carrier mobility in the(FAPb I_(3))0.95(MAPbI_(3))0.05should be related with the lattice distortion and enhanced electron–phonon coupling induced by the substitution.In addition,(FAPbI_(3))0.95(MAPbI_(3))0.05will lose fewer active carriers during the polaron cooling process than that in(FAPb I_(3))0.85(MAPbBr_(3)),indicating lower thermal dissipation in(FAPbI_(3))0.95(MAPbI_(3))0.05.Our results suggest that besides the smaller bandgap,the higher polaron mobility improved by the substitution engineering inα-FAPbI_(3)can also be an important factor for the high PCE of the black phaseα-FAPbI_(3)based solar cell devices.展开更多
The underlying mechanism of the spectral cleaning effect of the cross-polarized wave（XPW） generation process was theoretically investigated. This study shows that the spectral noise of an input spectrum can be remov...The underlying mechanism of the spectral cleaning effect of the cross-polarized wave（XPW） generation process was theoretically investigated. This study shows that the spectral noise of an input spectrum can be removed in the XPW generation process and that the spectral cleaning effect depends on the characteristics of the input pulses, such as the chirp and Fourier-transform-limited duration of the initial pulse, and the modulation amplitude and frequency of the spectral noise. Though these factors codetermine the output spectrum of the XPW generation process, the spectral cleaning effect is mainly affected by the initial pulse chirp. The smoothing of the spectrum in the XPW generation process leads to a significant enhancement of the coherent contrast.展开更多
This paper provides an overview of the current status of ultrafast and ultra-intense lasers with peak powers exceeding100 TW and examines the research activities in high-energy-density physics within China.Currently,1...This paper provides an overview of the current status of ultrafast and ultra-intense lasers with peak powers exceeding100 TW and examines the research activities in high-energy-density physics within China.Currently,10 high-intensity lasers with powers over 100 TW are operational,and about 10 additional lasers are being constructed at various institutes and universities.These facilities operate either independently or are combined with one another,thereby offering substantial support for both Chinese and international research and development efforts in high-energy-density physics.展开更多
We presented a broadband optical parametric chirped pulse amplification(OPCPA)system based on dual-crystal spectra cascading amplification in the short-wave infrared(SWIR)region.By cascading two crystals with differen...We presented a broadband optical parametric chirped pulse amplification(OPCPA)system based on dual-crystal spectra cascading amplification in the short-wave infrared(SWIR)region.By cascading two crystals with different phase-matching angles,the impact of gain bandwidth narrowing in OPCPA is reduced.In addition,due to the different phase-matching wavelengths,the energy backflow of the idler pulses is also mitigated,thereby enhancing the overall energy conversion efficiency of the system.Ultimately,SWIR pulses with a full-width at half-maximum(FWHM)exceeding 110 nm,a near Fourier-transform limit(FTL)pulse duration of 42.15 fs,and a pulse energy of 30 mJ are obtained(25.9%pump energy conversion efficiency),corresponding to a peak power of 0.75 TW.Compared to single-crystal amplification,this configuration achieves an 80 nm expansion in FWHM,the output pulse duration is reduced by more than 40%,the pump efficiency is increased by 17.22%,and a 2.3-time enhancement in peak power is achieved.This high-energy,terawatt-class SWIR source has significant applications in strong-field physics,including high-intensity THz and water-window X-ray generation,among other areas.展开更多
The betatron radiation source features a micrometer-scale source size,a femtosecond-scale pulse duration,milliradianlevel divergence angles and a broad spectrum exceeding tens of keV.It is conducive to the high-contra...The betatron radiation source features a micrometer-scale source size,a femtosecond-scale pulse duration,milliradianlevel divergence angles and a broad spectrum exceeding tens of keV.It is conducive to the high-contrast imaging of minute structures and for investigating interdisciplinary ultrafast processes.In this study,we present a betatron X-ray source derived from a high-charge,high-energy electron beam through a laser wakefield accelerator driven by the 1 PW/0.1 Hz laser system at the Shanghai Superintense Ultrafast Laser Facility(SULF).The critical energy of the betatron X-ray source is 22±5 keV.The maximum X-ray flux reaches up to 4×10^(9)photons for each shot in the spectral range of 5-30 keV.Correspondingly,the experiment demonstrates a peak brightness of 1.0×10^(23)photons·s^(-1)·mm^(-2)·mrad^(-2)·0.1%BW^(-1),comparable to those demonstrated by third-generation synchrotron light sources.In addition,the imaging capability of the betatron X-ray source is validated.This study lays the foundation for future imaging applications.展开更多
Vacuum-deposited perovskite light-emitting diodes(PeLEDs)have demonstrated significant potential for high-colorgamut active-matrix displays.Despite the rapid advance of green PeLEDs,red ones remain a considerable chal...Vacuum-deposited perovskite light-emitting diodes(PeLEDs)have demonstrated significant potential for high-colorgamut active-matrix displays.Despite the rapid advance of green PeLEDs,red ones remain a considerable challenge because of the inferior photophysical properties of vacuum-deposited red-light-emitting materials.Here,a rationally designed fluorine-modified phosphine oxide additive was introduced to in-situ passivate vacuum-deposited perovskites.The highly polar 2-F-TPPO incorporated perovskite films demonstrated enhanced photoluminescence quantum yield(PLQY),suppressed defects,and improved crystallinity.When implemented as active layers in PeLEDs,an external quantum efficiency(EQE)of 12.6%with an emission wavelength of 640 nm is achieved,which was 6 times higher compared to the previously reported most efficient vacuum-deposited red PeLEDs(EQE below 2%).Our findings lay the foundations for the further exploration of high-performance vacuum-deposited PeLEDs toward fullcolor perovskite displays.展开更多
This work investigates spatial evolution characteristics during second-harmonic generation(SHG)through numerical and experimental study by employing a dual-pass Nd:YLF amplifier chain.Through simultaneous monitoring o...This work investigates spatial evolution characteristics during second-harmonic generation(SHG)through numerical and experimental study by employing a dual-pass Nd:YLF amplifier chain.Through simultaneous monitoring of conversion efficiency dynamics and beam profile evolution,we demonstrate that the spatial uniformity follows deterministic transformation patterns during nonlinear frequency conversion.Notably,optimization of beam uniformity was achieved at the fundamental power density of 0.478 GW/cm2in our configuration,while maintaining conversion efficiency exceeding 85%.展开更多
We presented a repetition-rate tunable Yb-doped fiber laser system,which used a chirped fiber Bragg grating as a fiber stretcher designed to match the second-and third-order dispersion of the transmission grating comp...We presented a repetition-rate tunable Yb-doped fiber laser system,which used a chirped fiber Bragg grating as a fiber stretcher designed to match the second-and third-order dispersion of the transmission grating compressor.The system delivered 1-μJ,143-fs pulses at a 2 MHz repetition rate and 10-μJ,157-fs pulses at a 200 kHz repetition rate,respectively.The pulse repetition rate can be tuned from 200 kHz to 2 MHz while the pulse duration maintains<180 fs.This compact fiber laser source was built for applications in ophthalmology,such as corneal flap cutting and tissue vaporization.Furthermore,it can be applied in micro-machining applications,such as laser marking,scribing,and drilling.展开更多
A high-energy and high-efficiency 2μm nanosecond optical parametric oscillator(OPO)with excellent energy stability is reported.The cavity adopts a plane–plane configuration with two potassium titanyl phosphate(KTP)c...A high-energy and high-efficiency 2μm nanosecond optical parametric oscillator(OPO)with excellent energy stability is reported.The cavity adopts a plane–plane configuration with two potassium titanyl phosphate(KTP)crystals inserted using a spatial walk-off compensated orientation.The KTP-OPO is pumped by a 1064 nm Nd:YAG Q-switched laser at a repetition rate of 10 Hz and produces a maximum pulse energy of 162.6 m J at a pump energy of 431 m J,corresponding to an optical conversion efficiency of 37.7%and a slope efficiency of 45.2%.The energy stability shows a record root mean square(RMS)of0.4%over 30 min.To our knowledge,this represents the highest 2μm pulse energy achieved via the 1μm laser-pumped KTPOPO scheme,which could be an excellent laser source for driving extreme ultraviolet(EUV)radiations in the subsequent demonstration experiments.展开更多
The size of compression gratings has become a crucial factor in achieving 100-PW level super-intense ultrafast lasers,in view of the laser-induced damage of grating compressor.To improve the output laser energy within...The size of compression gratings has become a crucial factor in achieving 100-PW level super-intense ultrafast lasers,in view of the laser-induced damage of grating compressor.To improve the output laser energy within the damage threshold of grating compressor and therefore obtain higher laser peak power,we proposed the full-aperture grating compressor(FAGC).In this work,the spatiotemporal characteristics of the output pulses from FAGC are investigated,based on the SULF-10 PW laser facility with~400-mm beam diameter.The simulation and proof-of-principle experiment show that the pulse duration and the focusing quality of the output pulses from an FAGC are basically identical with those from a conventional 4-grating compressor;meanwhile,no evident diffractions are induced by the spectral clipping of FAGC.Thus,there is no marked influence of FAGC on the spatiotemporal characteristics of output compressed pulses.This work further demonstrates the feasibility of FAGC efficiently,which should be a promising scheme for realizing single-channel 100-PW level super-intense ultrafast lasers.展开更多
With the development of high-volume manufacturing for very-large-scale integrated circuits,the purity of the light source in the extreme ultraviolet lithography(EUVL)system needs to fulfil extreme requirements in orde...With the development of high-volume manufacturing for very-large-scale integrated circuits,the purity of the light source in the extreme ultraviolet lithography(EUVL)system needs to fulfil extreme requirements in order to avoid thermal effect,optical distortion and critical dimension errors caused by out-of-band radiations.This paper reviews the key technologies and developments of the spectral purity systems for both a free-standing system and a built-in system integrated with the collector.The main challenges and developing trends are also discussed,with a view towards practical applications for further improvement.Designing and manufacturing spectral purity systems for EUVL is not a single task;rather,it requires systematic considerations for all relevant modules.Moreover,the requirement of spectral purity filters drives the innovation in filtering technologies,optical micromachining and advanced metrology.展开更多
A femtosecond mid-infrared optical vortex laser can be used for high harmonic generation to extend cutoff energy to the kilo-electron-volt range with orbital angular momentum,as well as other secondary radiations.For ...A femtosecond mid-infrared optical vortex laser can be used for high harmonic generation to extend cutoff energy to the kilo-electron-volt range with orbital angular momentum,as well as other secondary radiations.For these,we demonstrate a high-energy femtosecond 4μm optical vortex laser based on optical parametric chirped pulse amplification(OPCPA)for the first time.The optical vortex seed is generated from a femtosecond 4μm laser by a silicon spiral phase plate with the topological charge l of 1 before the stretcher.Through using a two-stage collinear OPCPA amplifier,the chirped vortex pulse is amplified to 12.4 m J with 200 nm full width at half-maximum bandwidth.After compression,the vortex laser pulse with 9.53 m J,119 fs can be obtained.Furthermore,the vortex characteristics of the laser beam are investigated and evaluated.This demonstration can scale to generate a higher-peak-power vortex mid-IR laser and pave a new way for high field physics.展开更多
A high-brightness ultrabroadband supercontinuum white laser is desirable for various fields of modern science.Here,we present an intense ultraviolet-visible-infrared full-spectrum femtosecond laser source(with 300–50...A high-brightness ultrabroadband supercontinuum white laser is desirable for various fields of modern science.Here,we present an intense ultraviolet-visible-infrared full-spectrum femtosecond laser source(with 300–5000 nm 25 dB bandwidth)with 0.54 mJ per pulse.The laser is obtained by sending a 3.9μm,3.3 mJ mid-infrared pump pulse into a cascaded architecture of gas-filled hollow-core fiber,a bare lithium niobate crystal plate,and a specially designed chirped periodically poled lithium niobate crystal,under the synergic action of second and third order nonlinearities such as high harmonic generation and self-phase modulation.This full-spectrum femtosecond laser source can provide a revolutionary tool for optical spectroscopy and find potential applications in physics,chemistry,biology,material science,industrial processing,and environment monitoring.展开更多
Supercontinuum(SC)light source has advanced ultrafast laser spectroscopy in condensed matter science,biology,physics,and chemistry.Compared to the frequently used photonic crystal fibers and bulk materials,femtosecond...Supercontinuum(SC)light source has advanced ultrafast laser spectroscopy in condensed matter science,biology,physics,and chemistry.Compared to the frequently used photonic crystal fibers and bulk materials,femtosecond laser filamentation in gases is damage-immune for supercontinuum generation.A bottleneck problem is the strong jitters from filament induced self-heating at kHz repetition rate level.We demonstrated stable kHz supercontinuum generation directly in air with multiple mJ level pulse energy.This was achieved by applying an external DC electric field to the air plasma filament.Beam pointing jitters of the 1 kHz air filament induced SC light were reduced by more than 2 fold.The stabilized high repetition rate laser filament offers the opportunity for stable intense SC generation and its applications in air.展开更多
基金supported by grants from the Core Program grants of Guizhou Province,China(Grant No.QKHZDZXZ[2024]28)the Guizhou Provincial Science and Technology Projects of China(Grant No.YQK[2023]008)the Guizhou Provincial Scientific and Technological Program(Grant No.QKHFQ[2024]004-1).
文摘Blueberry(Vaccinium ashei)is highly characterized by its nutritional value,with an extremely high anthocyanin content,and rabbiteye blueberry is widely grown across China.However,molecular regulatory mechanisms underlying the high anthocyanin accumulation during the fruit development and colouration of rabbiteye blueberry fruit,have not yet been fully clarified so far.The fruit anthocyanin content of rabbiteye blueberry in the karstic area of Guizhou Province,China,is much higher compared to that in other regions,and the fruit colour is highly affected by anthocyanin accumulation.Currently,the untargeted metabolomics and HPLC assays have been carried out using rabbiteye blueberry fruit at various stages,and it was investigated that cyanidin(Cy)and pelargonidin(Pg)reached their peaks at the red fruit(RF)stage,whereas delphinidin(Dp),petudinin(Pt),malvidin(Mv),and peonidin(Pn)got their ceilings at the mature fruit(MF)stage.Transcriptome and co-expression network analyses showed that 27 differentially expressed genes(DEGs)were associated with anthocyanin content,among which VdMYB56,belonging to the R2R3-MYB family,was markedly up-regulated during the development and colouration of fruit,and was significantly higher in the skin than in the pulp.Furthermore,VdMYB56-overexpressing tomato fruits demonstrated a substantial elevation in anthocyanin content on the 35th day after flowering(DAF).It was worth noting that VdMYB56 could directly bind to the promoter of Vd3GT to enhance its expression,thereby further strengthening the anthocyanin accumulation.Meantime,multiple assays verified that VdMYB69,an R2R3-MYB member,might interact with VdMYB56,leading to the promotion of VdMYB56 expression.Conclusively,the VdMYB56-VdMYB69 module is a positive regulator of anthocyanin biosynthesis in rabbiteye blueberry,which may provide new insights into high-anthocyanin breeding,particularly for the southern karstic regions.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1604401)the Shanghai Science and Technology Committee Program(Grant Nos.22560780100 and 23560750200)the National Natural Science Foundation of China(Grant No.61925507)。
文摘Compressing all the energy of a laser pulse into a spatiotemporal focal cube edged by the laser center wavelength will realize the highest intensity of an ultra-intense ultrashort laser,which is called theλ^(3) regime or theλ^(3) laser.Herein,we introduced a rotational hyperbolic mirror—an important rotational conic section mirror with two foci—that is used as a secondary focusing mirror after a rotational parabolic mirror to reduce the focal spot size from several wavelengths to a single wavelength by significantly increasing the focusing angular aperture.Compared with the rotational ellipsoidal mirror,the first focal spot with a high intensity,as well as some unwanted strong-field effects,is avoided.The optimal focusing condition of this method is presented and the enhanced tight focusing for a femtosecond petawatt laser and theλ3 laser is numerically simulated,which can enhance the focused intensities of ultra-intense ultrashort lasers for laser physics.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1604401)the Shanghai Science and Technology Committee Program(Grant Nos.22560780100 and 23560750200)the National Natural Science Foundation of China(Grant No.61925507).
文摘After reaching a world record of 10 PW,the peak power development of the titanium-sapphire(Ti:sapphire)PW ultraintense lasers has hit a bottleneck,and it seems to be difficult to continue increasing due to the difficulty of manufacturing larger Ti:sapphire crystals and the limitation of parasitic lasing that can consume stored pump energy.Unlike coherent beam combining,coherent Ti:sapphire tiling is a viable solution for expanding Ti:sapphire crystal sizes,truncating transverse amplified spontaneous emission,suppressing parasitic lasing,and,importantly,not requiring complex space-time tiling control.A theoretical analysis of the above features and an experimental demonstration of high-quality laser amplification are reported.The results show that the addition of a 2×2 tiled Ti:sapphire amplifier to today’s 10 PW ultraintense laser is a viable technique to break the 10 PW limit and directly increase the highest peak power recorded by a factor of 4,further approaching the exawatt class.
基金supported by the National Natural Science Foundation of China(Nos.92050203,61905264,61925507,61875211,61674023,62005296,and 62105347)the National Key R&D Program of China 2017YFE0123700+1 种基金Shanghai Pilot Program for Basic Research(22JC1403200)the CAS Interdisciplinary Innovation Team。
文摘Lead halide hybrid perovskites(LHP)have emerged as one of the most promising photovoltaic materials for their remarkable solar energy conversion ability.The transportation of the photoinduced carriers in LHP could screen the defect recombination with the help of the large polaron formation.However,the physical insight of the relationship between the superior optical-electronic performance of perovskite and its polaron dynamics related to the electron-lattice strong coupling induced by the substitution engineering is still lack of investigation.Here,the bandgap modulated thin films ofα-FAPbI_(3)with different element substitution is investigated by the time resolved Terahertz spectroscopy.We find the polaron recombination dynamics could be prolonged in LHP with a relatively smaller bandgap,even though the formation of polaron will not be affected apparently.Intuitively,the large polaron mobility in(FAPb I_(3))0.95(MAPbI_(3))0.05thin film is~30%larger than that in(FAPb I_(3))0.85(MAPbBr_(3))0.15.The larger mobility in(FAPb I_(3))0.95(MAPb I_(3))0.05could be assigned to the slowing down of the carrier scattering time.Therefore,the physical origin of the higher carrier mobility in the(FAPb I_(3))0.95(MAPbI_(3))0.05should be related with the lattice distortion and enhanced electron–phonon coupling induced by the substitution.In addition,(FAPbI_(3))0.95(MAPbI_(3))0.05will lose fewer active carriers during the polaron cooling process than that in(FAPb I_(3))0.85(MAPbBr_(3)),indicating lower thermal dissipation in(FAPbI_(3))0.95(MAPbI_(3))0.05.Our results suggest that besides the smaller bandgap,the higher polaron mobility improved by the substitution engineering inα-FAPbI_(3)can also be an important factor for the high PCE of the black phaseα-FAPbI_(3)based solar cell devices.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11127901,61521093,and 61505234)the International S&T Cooperation of Program of China(Grant No.2016YFE0119300)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB160301)the Youth Innovation Promotion Association,Chinese Academy of Sciences
文摘The underlying mechanism of the spectral cleaning effect of the cross-polarized wave（XPW） generation process was theoretically investigated. This study shows that the spectral noise of an input spectrum can be removed in the XPW generation process and that the spectral cleaning effect depends on the characteristics of the input pulses, such as the chirp and Fourier-transform-limited duration of the initial pulse, and the modulation amplitude and frequency of the spectral noise. Though these factors codetermine the output spectrum of the XPW generation process, the spectral cleaning effect is mainly affected by the initial pulse chirp. The smoothing of the spectrum in the XPW generation process leads to a significant enhancement of the coherent contrast.
文摘This paper provides an overview of the current status of ultrafast and ultra-intense lasers with peak powers exceeding100 TW and examines the research activities in high-energy-density physics within China.Currently,10 high-intensity lasers with powers over 100 TW are operational,and about 10 additional lasers are being constructed at various institutes and universities.These facilities operate either independently or are combined with one another,thereby offering substantial support for both Chinese and international research and development efforts in high-energy-density physics.
基金National Key Research and Development Program of China(2023YFA1608504,2022YFA1604401)National Natural Science Foundation of China(12388102,22227901,62305353,U22A2090)+2 种基金Shanghai Science and Technology Committee Program(22DZ1100300,22560780100,23560750200)Talent Plan of Shanghai Branch,Chinese Academy of SciencesCAS Project for Young Scientists in Basic Research(YSBR-115).
文摘We presented a broadband optical parametric chirped pulse amplification(OPCPA)system based on dual-crystal spectra cascading amplification in the short-wave infrared(SWIR)region.By cascading two crystals with different phase-matching angles,the impact of gain bandwidth narrowing in OPCPA is reduced.In addition,due to the different phase-matching wavelengths,the energy backflow of the idler pulses is also mitigated,thereby enhancing the overall energy conversion efficiency of the system.Ultimately,SWIR pulses with a full-width at half-maximum(FWHM)exceeding 110 nm,a near Fourier-transform limit(FTL)pulse duration of 42.15 fs,and a pulse energy of 30 mJ are obtained(25.9%pump energy conversion efficiency),corresponding to a peak power of 0.75 TW.Compared to single-crystal amplification,this configuration achieves an 80 nm expansion in FWHM,the output pulse duration is reduced by more than 40%,the pump efficiency is increased by 17.22%,and a 2.3-time enhancement in peak power is achieved.This high-energy,terawatt-class SWIR source has significant applications in strong-field physics,including high-intensity THz and water-window X-ray generation,among other areas.
基金supported by the National Natural Science Foundation of China(Grant Nos.12388102,12225411,12105353 and 12174410)the CAS Project for Young Scientists in Basic Research(Grant No.YSBR060)+3 种基金the Program of Shanghai Academic Research Leader(Grant No.22XD1424200)the State Key Laboratory Program of the Chinese Ministry of Science and Technologythe CAS Youth Innovation Promotion Association(Grant No.2022242)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDB0890201 and XDB0890202)。
文摘The betatron radiation source features a micrometer-scale source size,a femtosecond-scale pulse duration,milliradianlevel divergence angles and a broad spectrum exceeding tens of keV.It is conducive to the high-contrast imaging of minute structures and for investigating interdisciplinary ultrafast processes.In this study,we present a betatron X-ray source derived from a high-charge,high-energy electron beam through a laser wakefield accelerator driven by the 1 PW/0.1 Hz laser system at the Shanghai Superintense Ultrafast Laser Facility(SULF).The critical energy of the betatron X-ray source is 22±5 keV.The maximum X-ray flux reaches up to 4×10^(9)photons for each shot in the spectral range of 5-30 keV.Correspondingly,the experiment demonstrates a peak brightness of 1.0×10^(23)photons·s^(-1)·mm^(-2)·mrad^(-2)·0.1%BW^(-1),comparable to those demonstrated by third-generation synchrotron light sources.In addition,the imaging capability of the betatron X-ray source is validated.This study lays the foundation for future imaging applications.
基金supported by the National Natural Science Foundation of China(62322505,62425502,62374069,62375060,62375276,U23A6002,and 62104077)Shanghai Pilot Program for Basic Research(22JC1403200)+2 种基金“Pioneer”and“Leading Goose”R&D Program of Zhejiang(2024C01192)the Natural Science Foundation of Hubei Province(2024AFB423 and 2023BAB102)the National Key Research and Development Program of China(2021YFB3501800,2023YFB3608903,2024YFA1209503).
文摘Vacuum-deposited perovskite light-emitting diodes(PeLEDs)have demonstrated significant potential for high-colorgamut active-matrix displays.Despite the rapid advance of green PeLEDs,red ones remain a considerable challenge because of the inferior photophysical properties of vacuum-deposited red-light-emitting materials.Here,a rationally designed fluorine-modified phosphine oxide additive was introduced to in-situ passivate vacuum-deposited perovskites.The highly polar 2-F-TPPO incorporated perovskite films demonstrated enhanced photoluminescence quantum yield(PLQY),suppressed defects,and improved crystallinity.When implemented as active layers in PeLEDs,an external quantum efficiency(EQE)of 12.6%with an emission wavelength of 640 nm is achieved,which was 6 times higher compared to the previously reported most efficient vacuum-deposited red PeLEDs(EQE below 2%).Our findings lay the foundations for the further exploration of high-performance vacuum-deposited PeLEDs toward fullcolor perovskite displays.
基金supported by the National Key R&D Program of China(Nos.2024YFB3613605,2022YFA160440,and 2019YFF01014401)the National Natural Science Foundation of China(Nos.61925507,12388102,62075227,and U21A20138)+3 种基金the National Major Scientific Research Instrument Development Project(No.22227901)the XDB(No.0890101)the Shanghai Rising-Star Program(No.21QA1410200)the Shanghai Science and Technology Committee Program(Nos.22DZ1100300,22560780100,and 23560750200)。
文摘This work investigates spatial evolution characteristics during second-harmonic generation(SHG)through numerical and experimental study by employing a dual-pass Nd:YLF amplifier chain.Through simultaneous monitoring of conversion efficiency dynamics and beam profile evolution,we demonstrate that the spatial uniformity follows deterministic transformation patterns during nonlinear frequency conversion.Notably,optimization of beam uniformity was achieved at the fundamental power density of 0.478 GW/cm2in our configuration,while maintaining conversion efficiency exceeding 85%.
基金supported by the National Key Research and Development Program of China(Nos.2024YFB3613502 and 2023YFB3307702)the Shanghai Pujiang Program(No.23PJ1414700)the National Natural Science Foundation of China(No.62435005)。
文摘We presented a repetition-rate tunable Yb-doped fiber laser system,which used a chirped fiber Bragg grating as a fiber stretcher designed to match the second-and third-order dispersion of the transmission grating compressor.The system delivered 1-μJ,143-fs pulses at a 2 MHz repetition rate and 10-μJ,157-fs pulses at a 200 kHz repetition rate,respectively.The pulse repetition rate can be tuned from 200 kHz to 2 MHz while the pulse duration maintains<180 fs.This compact fiber laser source was built for applications in ophthalmology,such as corneal flap cutting and tissue vaporization.Furthermore,it can be applied in micro-machining applications,such as laser marking,scribing,and drilling.
基金supported by the National Key R&D Program of China(No.2022YFA1604401)the National Natural Science Foundation of China(Nos.12388102,62205351,61925507,62075227,and 22227901)+2 种基金the Shanghai Science and Technology Committee Program(Nos.22DZ1100300,22560780100,and 23560750200)the Shanghai Rising-Star Program(No.21QA1410200)the Youth Innovation Promotion Association CAS(No.2020248).
文摘A high-energy and high-efficiency 2μm nanosecond optical parametric oscillator(OPO)with excellent energy stability is reported.The cavity adopts a plane–plane configuration with two potassium titanyl phosphate(KTP)crystals inserted using a spatial walk-off compensated orientation.The KTP-OPO is pumped by a 1064 nm Nd:YAG Q-switched laser at a repetition rate of 10 Hz and produces a maximum pulse energy of 162.6 m J at a pump energy of 431 m J,corresponding to an optical conversion efficiency of 37.7%and a slope efficiency of 45.2%.The energy stability shows a record root mean square(RMS)of0.4%over 30 min.To our knowledge,this represents the highest 2μm pulse energy achieved via the 1μm laser-pumped KTPOPO scheme,which could be an excellent laser source for driving extreme ultraviolet(EUV)radiations in the subsequent demonstration experiments.
基金supported by the National Key R&D Program of China(2020YFA0714500,2019YFF01014401)The National Natural Science Foundation of China(12388102)+2 种基金Strategic Priority Research Program of Chinese Academy of Sciences(XDB0890102)Shanghai Science and Technology Committee Program(22DZ1100300,22560780100,23560750200)The Youth Innovation Promotion Association of the Chinese Academy of Sciences.
文摘The size of compression gratings has become a crucial factor in achieving 100-PW level super-intense ultrafast lasers,in view of the laser-induced damage of grating compressor.To improve the output laser energy within the damage threshold of grating compressor and therefore obtain higher laser peak power,we proposed the full-aperture grating compressor(FAGC).In this work,the spatiotemporal characteristics of the output pulses from FAGC are investigated,based on the SULF-10 PW laser facility with~400-mm beam diameter.The simulation and proof-of-principle experiment show that the pulse duration and the focusing quality of the output pulses from an FAGC are basically identical with those from a conventional 4-grating compressor;meanwhile,no evident diffractions are induced by the spectral clipping of FAGC.Thus,there is no marked influence of FAGC on the spatiotemporal characteristics of output compressed pulses.This work further demonstrates the feasibility of FAGC efficiently,which should be a promising scheme for realizing single-channel 100-PW level super-intense ultrafast lasers.
基金This work was supported by the Science and Technology Commission of Shanghai Municipality(No.22DZ1100300).
文摘With the development of high-volume manufacturing for very-large-scale integrated circuits,the purity of the light source in the extreme ultraviolet lithography(EUVL)system needs to fulfil extreme requirements in order to avoid thermal effect,optical distortion and critical dimension errors caused by out-of-band radiations.This paper reviews the key technologies and developments of the spectral purity systems for both a free-standing system and a built-in system integrated with the collector.The main challenges and developing trends are also discussed,with a view towards practical applications for further improvement.Designing and manufacturing spectral purity systems for EUVL is not a single task;rather,it requires systematic considerations for all relevant modules.Moreover,the requirement of spectral purity filters drives the innovation in filtering technologies,optical micromachining and advanced metrology.
基金Strategic Priority Research Program of the Chinese Academy of Sciences(XDB1603)International ST Cooperation Program of China(2016YFE0119300)+2 种基金Program of Shanghai Academic/Technology Research Leader(18XD1404200)Shanghai Municipal Science and Technology Major Project(2017SHZDZX02)National Natural Science Foundation of China(11127901,61925507)。
文摘A femtosecond mid-infrared optical vortex laser can be used for high harmonic generation to extend cutoff energy to the kilo-electron-volt range with orbital angular momentum,as well as other secondary radiations.For these,we demonstrate a high-energy femtosecond 4μm optical vortex laser based on optical parametric chirped pulse amplification(OPCPA)for the first time.The optical vortex seed is generated from a femtosecond 4μm laser by a silicon spiral phase plate with the topological charge l of 1 before the stretcher.Through using a two-stage collinear OPCPA amplifier,the chirped vortex pulse is amplified to 12.4 m J with 200 nm full width at half-maximum bandwidth.After compression,the vortex laser pulse with 9.53 m J,119 fs can be obtained.Furthermore,the vortex characteristics of the laser beam are investigated and evaluated.This demonstration can scale to generate a higher-peak-power vortex mid-IR laser and pave a new way for high field physics.
基金The authors are grateful for the financial support from the Science and Technology Project of Guangdong(2020B010190001)National Natural Science Foundation of China(11974119,61925507,62075227)+3 种基金Guangdong Innovative and Entrepreneurial Research Team Program(2016ZT06C594)National Key R&D Program of China(2018YFA 0306200)Shanghai Rising-Star Program(21QA1410200)Youth Innovation Promotion Association CAS(2020248).
文摘A high-brightness ultrabroadband supercontinuum white laser is desirable for various fields of modern science.Here,we present an intense ultraviolet-visible-infrared full-spectrum femtosecond laser source(with 300–5000 nm 25 dB bandwidth)with 0.54 mJ per pulse.The laser is obtained by sending a 3.9μm,3.3 mJ mid-infrared pump pulse into a cascaded architecture of gas-filled hollow-core fiber,a bare lithium niobate crystal plate,and a specially designed chirped periodically poled lithium niobate crystal,under the synergic action of second and third order nonlinearities such as high harmonic generation and self-phase modulation.This full-spectrum femtosecond laser source can provide a revolutionary tool for optical spectroscopy and find potential applications in physics,chemistry,biology,material science,industrial processing,and environment monitoring.
基金This work was supported in part by NSAF(Grant No.U2130123)the International Partnership Program of Chinese Academy of Sciences(Grant Nos.181231KYSB20200033 and 181231KYSB20200040)Shanghai Science and Technology Program(Grant No.21511105000).S.L.C.acknowledges the support of COPL,Laval University,Quebec City,Canada.We thank Dr.Hao Guo,Ms.Na Chen,Mr.Xuan Zhang,Dr.Haiyi Sun from SIOM for help in the experiments and Prof.Howard M.Milchberg from the University of Maryland for the fruitful discussions and his reading of the manuscript.
文摘Supercontinuum(SC)light source has advanced ultrafast laser spectroscopy in condensed matter science,biology,physics,and chemistry.Compared to the frequently used photonic crystal fibers and bulk materials,femtosecond laser filamentation in gases is damage-immune for supercontinuum generation.A bottleneck problem is the strong jitters from filament induced self-heating at kHz repetition rate level.We demonstrated stable kHz supercontinuum generation directly in air with multiple mJ level pulse energy.This was achieved by applying an external DC electric field to the air plasma filament.Beam pointing jitters of the 1 kHz air filament induced SC light were reduced by more than 2 fold.The stabilized high repetition rate laser filament offers the opportunity for stable intense SC generation and its applications in air.
