When this article was originally published in High Power Laser Science and Engineering it contained an error in the name of the author Jiandong Liu.This has now been fixed.The publisher apologises for this error.
We present a novel scheme for rapid quantitative analysis of debris generated during experiments with solid targets following relativistic laser–plasma interaction at high-power laser facilities.Results are supported...We present a novel scheme for rapid quantitative analysis of debris generated during experiments with solid targets following relativistic laser–plasma interaction at high-power laser facilities.Results are supported by standard analysis techniques.Experimental data indicate that predictions by available modelling for non-mass-limited targets are reasonable,with debris of the order of hundreds ofμg per shot.We detect for the first time two clearly distinct types of debris emitted from the same interaction.A fraction of the debris is ejected directionally,following the target normal(rear and interaction side).The directional debris ejection towards the interaction side is larger than on the side of the target rear.The second type of debris is characterized by a more spherically uniform ejection,albeit with a small asymmetry that favours ejection towards the target rear side.展开更多
High-power lasers are vital for particle acceleration,imaging,fusion and materials processing,requiring precise control and high-energy delivery.Laser plasma accelerators(LPAs)demand laser positional stability at focu...High-power lasers are vital for particle acceleration,imaging,fusion and materials processing,requiring precise control and high-energy delivery.Laser plasma accelerators(LPAs)demand laser positional stability at focus to ensure consistent electron beams in applications such as X-ray free-electron lasers and high-energy colliders.Achieving this stability is especially challenging for the low-repetition-rate lasers in current LPAs.We present a machine learning method that predicts and corrects laser pointing instabilities in real-time using a high-frequency pilot beam.By preemptively adjusting a correction mirror,this approach overcomes traditional feedback limits.Demonstrated on the BELLA petawatt laser operating at the terawatt level(30 mJ amplification),our method achieved root mean square pointing stabilization of 0.34 and 0.59μrad in the x and y directions,reducing jitter by 65%and 47%,respectively.This is the first successful application of predictive control for shot-to-shot stabilization in low-repetition-rate laser systems,paving the way for full-energy petawatt lasers and transformative advances across science,industry and security.展开更多
Accurate characterization of high-power laser parameters,especially the near-field and far-field distributions,is crucial for inertial confinement fusion experiments.In this paper,we propose a method for computational...Accurate characterization of high-power laser parameters,especially the near-field and far-field distributions,is crucial for inertial confinement fusion experiments.In this paper,we propose a method for computationally reconstructing the complex amplitude of high-power laser beams using modified coherent modulation imaging.This method has the advantage of being able to simultaneously calculate both the near-field(intensity and wavefront/phase)and far-field(focal-spot)distributions using the reconstructed complex amplitude.More importantly,the focal-spot distributions at different focal planes can also be calculated.To verify the feasibility,the complex amplitude optical field of the highpower pulsed laser was measured after static aberrations calibration.Experimental results also indicate that the near-field wavefront resolution of this method is higher than that of the Hartmann measurement.In addition,the far-field focal spot exhibits a higher dynamic range(176 dB)than that of traditional direct imaging(62 dB).展开更多
Based on a 4f system,a 0?reflector and a single laser diode side-pump amplifier,a new amplifier is designed to compensate the spherical aberration of the amplified laser generated by a single laser diode side-pump amp...Based on a 4f system,a 0?reflector and a single laser diode side-pump amplifier,a new amplifier is designed to compensate the spherical aberration of the amplified laser generated by a single laser diode side-pump amplifier and enhance the power of the amplified laser.Furthermore,the role of the 4f system in the passive spherical aberration compensation and its effect on the amplified laser are discussed in detail.The results indicate that the amplification efficiency is enhanced by incorporating a 4f system in a double-pass amplifier and placing a 0?reflector only at the focal point of the single-pass amplified laser.This method also effectively uses the heat from the gain medium(neodymiumdoped yttrium aluminium garnet)of the amplifier to compensate the spherical aberration of the amplified laser.展开更多
Fast electron generation and transport in high-intensity laser–solid interactions induces X-ray emission and drives ion acceleration.Effective production of these sources hinges on an efficient laser absorption into ...Fast electron generation and transport in high-intensity laser–solid interactions induces X-ray emission and drives ion acceleration.Effective production of these sources hinges on an efficient laser absorption into the fast electron population and control of divergence as the beam propagates through the target.Nanowire targets can be employed to increase the laser absorption,but it is not yet clear how the fast electron beam properties are modified.Here we present novel measurements of the emittance of the exiting fast electron beam from irradiated solid planar and nanowire targets via a pepper-pot diagnostic.The measurements indicate a greater fast electron emittance is obtained from nanowire targets.Two-dimensional particle-in-cell simulations support this conclusion,revealing beam defocusing at the wire–substrate boundary,a higher fast electron temperature and transverse oscillatory motion around the wires.展开更多
We present coherent beam combining of nanosecond pulses with 20-J energy and large beams using a Sagnac interferometer geometry based on Nd:glass rod-type amplifiers.In this study,we demonstrate that coherent beam com...We present coherent beam combining of nanosecond pulses with 20-J energy and large beams using a Sagnac interferometer geometry based on Nd:glass rod-type amplifiers.In this study,we demonstrate that coherent beam combining is compatible with large-diameter energetic beams,presenting,therefore,an interesting and solid perspective towards the performance improvement of large-scale laser facilities,especially in terms of high-repetition-rate and highenergy operation.We demonstrate that for energy of 20 J,the coherent combination efficiency is around 92%,with high beam quality and long-term stability.A thorough temporal and spatial characterization of the system's operation is provided to forecast the various potentialities available for large-scale facilities.展开更多
When this article was originally published in High Power Laser Science and Engineering it omitted to include a couple of supplementary material files.These have now been published online.The publisher apologises for t...When this article was originally published in High Power Laser Science and Engineering it omitted to include a couple of supplementary material files.These have now been published online.The publisher apologises for this error.展开更多
We used the PW high-repetition laser facility VEGA-3 at Centro de Láseres Pulsados in Salamanca,with the goal of studying the generation of radioisotopes using laser-driven proton beams.Various types of targets h...We used the PW high-repetition laser facility VEGA-3 at Centro de Láseres Pulsados in Salamanca,with the goal of studying the generation of radioisotopes using laser-driven proton beams.Various types of targets have been irradiated including in particular several targets containing boron to generateα-particles through the hydrogen–boron fusion reaction.We have successfully identifiedγ-ray lines from several radioisotopes created by irradiation using lasergeneratedα-particles or protons including^(43)Sc,^(44)Sc,^(48)Sc,^(7)Be,^(11)C and^(18)F.We show that radioisotope generation can be used as a diagnostic tool to evaluateα-particle generation in laser-driven proton–boron fusion experiments.We also show the production of^(11)C radioisotopes,≈6×10~6,and of^(44)Sc radioisotopes,≈5×10~4per laser shot.This result can open the way to develop laser-driven radiation sources of radioisotopes for medical applications.展开更多
The immediate priorities for high-power delivery employing solid-core fibers are balancing the nonlinear effect and beam deterioration.Here,the scheme of tapered multimode fiber is experimentally realized.The tapered ...The immediate priorities for high-power delivery employing solid-core fibers are balancing the nonlinear effect and beam deterioration.Here,the scheme of tapered multimode fiber is experimentally realized.The tapered multimode fiber,featuring a 15 m(24/200μm)–10 m(tapered region)–80 m(48/400μm)profile,guides the laser with a weakly coupled condition.With the input power of 1035 W,the maximum output power over the 105 m delivery is 962 W,corresponding to a high efficiency of over 93%and a nonlinear suppression ratio of over 50 dB.Mode resolving results show high-order-mode contents of less than–30 dB in the whole delivery path,resulting in a high-fidelity delivery with M2 factors of 1.20 and 1.23 for the input and output lasers,respectively.Furthermore,the ultimate limits of delivery lengths for solid-core weakly coupled fibers are discussed.This work provides a valuable reference to reconsider the future boom of high-power laser delivery based on solid-core fibers.展开更多
Spatial intensity modulation in amplified laser beams,particularly hot spots,critically constrains attainable pulse peak power due to the damage threshold limitations of four-grating compressors.This study demonstrate...Spatial intensity modulation in amplified laser beams,particularly hot spots,critically constrains attainable pulse peak power due to the damage threshold limitations of four-grating compressors.This study demonstrates that the double-smoothing grating compressor(DSGC)configuration effectively suppresses modulation through directional beam smoothing.Our systematic investigation validated the double-smoothing effect through numerical simulations and experimental measurements,with comprehensive spatiotemporal analysis revealing excellent agreement between numerical and practical pulse characteristics.Crucially,the DSGC enables a 1.74 times energy output boost compared to conventional compressors.These findings establish the DSGC as a pivotal advancement for next-generation ultrahighpower laser systems,providing a viable pathway toward hundreds of PW output through optimized spatial energy redistribution.展开更多
Laser-driven inertial confinement fusion(ICF)diagnostics play a crucial role in understanding the complex physical processes governing ICF and enabling ignition.During the ICF process,the interaction between the high-...Laser-driven inertial confinement fusion(ICF)diagnostics play a crucial role in understanding the complex physical processes governing ICF and enabling ignition.During the ICF process,the interaction between the high-power laser and ablation material leads to the formation of a plasma critical surface,which reflects a significant portion of the driving laser,reducing the efficiency of laser energy conversion into implosive kinetic energy.Effective diagnostic methods for the critical surface remain elusive.In this work,we propose a novel optical diagnostic approach to investigate the plasma critical surface.This method has been experimentally validated,providing new insights into the critical surface morphology and dynamics.This advancement represents a significant step forward in ICF diagnostic capabilities,with the potential to inform strategies for enhancing the uniformity of the driving laser and target surface,ultimately improving the efficiency of converting laser energy into implosion kinetic energy and enabling ignition.展开更多
This paper presents an investigation of the secondary saturation characteristics of a HfTe_(2)saturable absorber.Pulse energies of 5.85 and 7.4 mJ were demonstrated with a high-order Hermite-Gaussian(HG)laser and a vo...This paper presents an investigation of the secondary saturation characteristics of a HfTe_(2)saturable absorber.Pulse energies of 5.85 and 7.4 mJ were demonstrated with a high-order Hermite-Gaussian(HG)laser and a vortex laser,respectively,using alexandrite as the gain medium.To the best of our knowledge,these are the highest pulse energies directly generated with HG and vortex lasers.To broaden the applications of high-energy pulsed HG and vortex lasers,wavelength tuning in the region of 40 nm was achieved using an etalon.pulse energy of 5.85 mJ and a vortex laser with a single pulse energy of 7.4 mJ were obtained in alexandrite.The repetition rates of these lasers were 262 and 196 Hz,respectively.To expand the applications of high-energy structured lasers,wavelength tuning within the range of 747-787 nm was successfully accomplished using an etalon.展开更多
This study investigates the influence of seismic activities on the optical synchronization system of the European X-ray Free-Electron Laser.We analyze the controller input/output data of phase-locked loops in length-s...This study investigates the influence of seismic activities on the optical synchronization system of the European X-ray Free-Electron Laser.We analyze the controller input/output data of phase-locked loops in length-stabilized links,focusing on the response to earthquakes,ocean-generated microseism and civilization noise.By comparing the controller data with external data,we were able to identify disturbances and their effects on the control signals.Our results show that seismic events influence the stability of the phase-locked loops.Even earthquakes that are approximately 5000 km away cause remarkable fluctuations in the in-loop control signals.Ocean-generated microseism in particular has an enormous influence on the in-loop control signals due to its constant presence.The optical synchronization system is so highly sensitive that it can even identify vibrations caused by civilization,such as road traffic or major events like concerts or sport events.The phase-locked loops manage to eliminate more than 99%of the existing interference.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
With the escalating laser peak power,modulating and detecting the intensity,duration,phase and polarization of ultraintense laser pulses progressively becomes increasingly arduous due to the limited damage thresholds ...With the escalating laser peak power,modulating and detecting the intensity,duration,phase and polarization of ultraintense laser pulses progressively becomes increasingly arduous due to the limited damage thresholds of conventional optical components.In particular,the generation and detection of ultra-intense vortex lasers pose great challenges for current laser technologies,which has limited the widely potential applications of relativistic vortex lasers in various domains.In this study,we propose to reconstruct the vortex phase and generate and amplify the relativistic vortex lasers via surface plasma holograms(SPHs).By interfering with the object laser and reference laser,SPHs are formed on the target and the phase of the interfering laser is imprinted through the modulation of surface plasma density.In particular,using the quadrature phase-shift interference,the vortex phase of the object laser can be well reconstructed.The generated vortex lasers can be focused and enhanced further by one order of magnitude,up to 1.7×10^(21)W/cm^(2),which has been demonstrated by full three-dimensional particle-in-cell simulations.For the first time,we provide a practical way to detect the phase of relativistic vortex lasers,which can be applied in large 1–10 PW laser facilities.This will promote future experimental research of vortex-laser–plasma interaction and open a new avenue of plasma optics in the ultra-relativistic regime.展开更多
Coherent combining of several low-energy few-cycle beams offers a reliable and feasible approach to producing fewcycle laser pulses with energies exceeding the multi-joule level.However,time synchronization and carrie...Coherent combining of several low-energy few-cycle beams offers a reliable and feasible approach to producing fewcycle laser pulses with energies exceeding the multi-joule level.However,time synchronization and carrier-envelope phase difference(ΔCEP)between pulses significantly affect the temporal waveform and intensity of the combined pulse,requiring precise measurement and control.Here,we propose a concise optical method based on the phase retrieval of spectral interference and quadratic function symmetry axis fitting to simultaneously measure the time synchronization andΔCEP between few-cycle pulses.The control precision of our coherent beam combining system can achieve a time delay stability within 42 as andΔCEP measurement precision of 40 mrad,enabling a maximum combining efficiency of 98.5%.This method can effectively improve the performance and stability of coherent beam combining systems for few-cycle lasers,which will facilitate the obtaining of high-quality few-cycle lasers with high energy.展开更多
The propagation of multiple ultraintense femtosecond lasers in underdense plasmas is investigated theoretically and numerically.We find that the energy merging effect between two in-phase seed lasers can be improved b...The propagation of multiple ultraintense femtosecond lasers in underdense plasmas is investigated theoretically and numerically.We find that the energy merging effect between two in-phase seed lasers can be improved by using two obliquely incident guiding lasers whose initial phase isπandπ/2 ahead of the seed laser.Particle-in-cell simulations show that due to the repulsion and energy transfer of the guiding laser,the peak intensity of the merged light is amplified by more than five times compared to the seed laser.The energy conversion efficiency from all incident lasers to the merged light is up to approximately 60%.The results are useful for many applications,including plasma-based optical amplification,charged particle acceleration and extremely intense magnetic field generation.展开更多
The effect of the polarizations of two counter-propagating relativistic laser pulses interacting with subwavelength thin solid-density foil is investigated.Three-dimensional particle-in-cell simulations and analytical...The effect of the polarizations of two counter-propagating relativistic laser pulses interacting with subwavelength thin solid-density foil is investigated.Three-dimensional particle-in-cell simulations and analytical modelling show that the interaction and resulting transverse instability depend strongly on the polarization directions as well as the intensity distribution of the resultant light field in the foil.The left-and right-handed circularly polarized laser pair with the same phase at the common focal spot in the ultrathin foil leads to the strongest distortion of the foil.The fastest growing mode and maximum growth rate depend mainly on the laser intensity.For all polarization and phase-difference combinations,the instability is weakest when the two laser pulses are exactly out of phase at the common focusing point in the foil.展开更多
In this work,we confirm a Pr^(3+):LiYF_(4)pulsed laser with high power and high energy at 639 nm based on the acoustooptic cavity dumping technique.The maximum average output power,narrowest pulse width,highest pulse ...In this work,we confirm a Pr^(3+):LiYF_(4)pulsed laser with high power and high energy at 639 nm based on the acoustooptic cavity dumping technique.The maximum average output power,narrowest pulse width,highest pulse energy and peak power of the pulsed laser at a repetition rate of 0.1 kHz are 532 mW,112 ns,5.32 mJ and 47.5 kW,respectively.A 639 nm pulsed laser with such high pulse energy and peak power has not been reported previously.Furthermore,we obtain a widely tunable range of repetition rates from 0.1 to 5000 kHz.The diffracted beam quality factors M^(2) are 2.18(in the x direction)and 2.04(in the y direction).To the best of our knowledge,this is the first time that a cavity-dumped all-solid-state pulsed laser in the visible band has been reported.This work provides a promising method for obtaining high-performance pulsed lasers.展开更多
文摘When this article was originally published in High Power Laser Science and Engineering it contained an error in the name of the author Jiandong Liu.This has now been fixed.The publisher apologises for this error.
基金funding from the European Union’s Horizon 2020 research and innovation programme through the European IMPULSE project under grant agreement No.871161 and LASERLAB-EUROPE V under grant agreement No.871124from grant PDC2021-120933-I00 funded by MCIN/AEI/10.13039/501100011033 and by the European Union Next Generation EU/PRTR+4 种基金from grant PID2021-125389OA-I00 funded by MCIN/AEI/10.13039/501100011033/FEDER,UE and by‘ERDF A way of making Europe’by the European Union and in addition to Unidad de Investigacion Consolidada de la Junta de Castilla y Leon No.CLP087U16The UPM47 campaign was funded through IOSIN,Nucleu PN-IFIN-HH 23-26 Code PN 2321the ELI-NP Phase II,a project co-financed by the Romanian Government and the European Union through the European Regional Development Fund and the Competitiveness Operational Programme(1/07.07.2016,COP,ID 1334)This research was funded,in part,by the French Agence Nationale de la Recherche(ANR),Project No.ANR-22-CE30-0044supported by the Ministry of Youth and Sports of the Czech Republic(Project Nos.LM2023068 and LM2018114(PALS RI)).
文摘We present a novel scheme for rapid quantitative analysis of debris generated during experiments with solid targets following relativistic laser–plasma interaction at high-power laser facilities.Results are supported by standard analysis techniques.Experimental data indicate that predictions by available modelling for non-mass-limited targets are reasonable,with debris of the order of hundreds ofμg per shot.We detect for the first time two clearly distinct types of debris emitted from the same interaction.A fraction of the debris is ejected directionally,following the target normal(rear and interaction side).The directional debris ejection towards the interaction side is larger than on the side of the target rear.The second type of debris is characterized by a more spherically uniform ejection,albeit with a small asymmetry that favours ejection towards the target rear side.
基金supported by the Office of Science,Office of High Energy Physics,of the US Department of Energythe Laboratory Directed Research and Development Program of Lawrence Berkeley National Laboratory under contract No.DE-AC02-05CH11231。
文摘High-power lasers are vital for particle acceleration,imaging,fusion and materials processing,requiring precise control and high-energy delivery.Laser plasma accelerators(LPAs)demand laser positional stability at focus to ensure consistent electron beams in applications such as X-ray free-electron lasers and high-energy colliders.Achieving this stability is especially challenging for the low-repetition-rate lasers in current LPAs.We present a machine learning method that predicts and corrects laser pointing instabilities in real-time using a high-frequency pilot beam.By preemptively adjusting a correction mirror,this approach overcomes traditional feedback limits.Demonstrated on the BELLA petawatt laser operating at the terawatt level(30 mJ amplification),our method achieved root mean square pointing stabilization of 0.34 and 0.59μrad in the x and y directions,reducing jitter by 65%and 47%,respectively.This is the first successful application of predictive control for shot-to-shot stabilization in low-repetition-rate laser systems,paving the way for full-energy petawatt lasers and transformative advances across science,industry and security.
基金supported by the Project of the Ministry of Industry and Information Technology(Grant No.TC220H05L)the National Natural Science Foundation of China(NSFC)(Grant Nos.61905261,61827816 and 11875308)+1 种基金the Shanghai Sailing Program(Grant No.18YF1426600)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA25020306).
文摘Accurate characterization of high-power laser parameters,especially the near-field and far-field distributions,is crucial for inertial confinement fusion experiments.In this paper,we propose a method for computationally reconstructing the complex amplitude of high-power laser beams using modified coherent modulation imaging.This method has the advantage of being able to simultaneously calculate both the near-field(intensity and wavefront/phase)and far-field(focal-spot)distributions using the reconstructed complex amplitude.More importantly,the focal-spot distributions at different focal planes can also be calculated.To verify the feasibility,the complex amplitude optical field of the highpower pulsed laser was measured after static aberrations calibration.Experimental results also indicate that the near-field wavefront resolution of this method is higher than that of the Hartmann measurement.In addition,the far-field focal spot exhibits a higher dynamic range(176 dB)than that of traditional direct imaging(62 dB).
基金supported by the National Natural Science Foundation of China(Grant Nos.62075056 and 61927815)the Natural Science Foundation of Hebei Province(Grant Nos.F2023202082 and F2022202035)。
文摘Based on a 4f system,a 0?reflector and a single laser diode side-pump amplifier,a new amplifier is designed to compensate the spherical aberration of the amplified laser generated by a single laser diode side-pump amplifier and enhance the power of the amplified laser.Furthermore,the role of the 4f system in the passive spherical aberration compensation and its effect on the amplified laser are discussed in detail.The results indicate that the amplification efficiency is enhanced by incorporating a 4f system in a double-pass amplifier and placing a 0?reflector only at the focal point of the single-pass amplified laser.This method also effectively uses the heat from the gain medium(neodymiumdoped yttrium aluminium garnet)of the amplifier to compensate the spherical aberration of the amplified laser.
基金the NextGenerationEU(PNRR)Integrated Infrastructure Initiative in Photonic and Quantum Sciences(IPHOQS)(CUP B53C22001750006,ID D2B8D520,IR0000016)EuPRAXIA Advanced Photon Sources(EuAPS)(CUP I93C21000160006,IR0000030)+3 种基金funding from the Engineering and Physical Sciences Research Council(EP/L01663X/1)the Royal Society International Exchange(IES/R3/170248)Computing resources were provided by STFC Scientific Computing Department’s SCARF clusterfunded by the UK EPSRC(grants EP/G054950/1,EP/G056803/1,EP/G055165/1 and EP/M022463/1).
文摘Fast electron generation and transport in high-intensity laser–solid interactions induces X-ray emission and drives ion acceleration.Effective production of these sources hinges on an efficient laser absorption into the fast electron population and control of divergence as the beam propagates through the target.Nanowire targets can be employed to increase the laser absorption,but it is not yet clear how the fast electron beam properties are modified.Here we present novel measurements of the emittance of the exiting fast electron beam from irradiated solid planar and nanowire targets via a pepper-pot diagnostic.The measurements indicate a greater fast electron emittance is obtained from nanowire targets.Two-dimensional particle-in-cell simulations support this conclusion,revealing beam defocusing at the wire–substrate boundary,a higher fast electron temperature and transverse oscillatory motion around the wires.
基金funding from the European Union’s HORIZON-INFRA-2022-TECH-01 call under grant agreement number 101095207funded by the‘SESAME filières PIA’call for projects from Bpifrance for the‘CRONOS’project,contract numbers DOS0153845/00 and DOS0153842/00。
文摘We present coherent beam combining of nanosecond pulses with 20-J energy and large beams using a Sagnac interferometer geometry based on Nd:glass rod-type amplifiers.In this study,we demonstrate that coherent beam combining is compatible with large-diameter energetic beams,presenting,therefore,an interesting and solid perspective towards the performance improvement of large-scale laser facilities,especially in terms of high-repetition-rate and highenergy operation.We demonstrate that for energy of 20 J,the coherent combination efficiency is around 92%,with high beam quality and long-term stability.A thorough temporal and spatial characterization of the system's operation is provided to forecast the various potentialities available for large-scale facilities.
文摘When this article was originally published in High Power Laser Science and Engineering it omitted to include a couple of supplementary material files.These have now been published online.The publisher apologises for this error.
基金supported by COST(European Cooperation in Science and Technology)through Action CA21128 PROBONO(PROton BOron Nuclear Fusion:from energy production to medical applicati Ons)funding from the European Union’s 2020 research and innovation program under grant agreement No.101008126(RADNEXT project)United States Department of Energy under grant#DEFG02-93ER40773+3 种基金SMILEI simulations were performed thanks to granted access to the HPC resources of TGCC under allocation No.2023-A0140514117 made by GENCIfinancial support of the Id Ex University of Bordeaux/Grand Research Program‘GPR LIGHT’and of the Graduate Program on Light Sciences and Technologies of the University of BordeauxL.G.and V.K.acknowledge the support of the Czech Science Foundation through grant No.GACR24-11398Ssupport of HB11 Energy,Ltd.,Australia,through its Collaborative Science Program.H.L.and M.H.
文摘We used the PW high-repetition laser facility VEGA-3 at Centro de Láseres Pulsados in Salamanca,with the goal of studying the generation of radioisotopes using laser-driven proton beams.Various types of targets have been irradiated including in particular several targets containing boron to generateα-particles through the hydrogen–boron fusion reaction.We have successfully identifiedγ-ray lines from several radioisotopes created by irradiation using lasergeneratedα-particles or protons including^(43)Sc,^(44)Sc,^(48)Sc,^(7)Be,^(11)C and^(18)F.We show that radioisotope generation can be used as a diagnostic tool to evaluateα-particle generation in laser-driven proton–boron fusion experiments.We also show the production of^(11)C radioisotopes,≈6×10~6,and of^(44)Sc radioisotopes,≈5×10~4per laser shot.This result can open the way to develop laser-driven radiation sources of radioisotopes for medical applications.
基金supported by the National Key R&D Program of China(No.2022YFB3606000)the Graduate Innovation Project of Hunan Province(No.QL20220004).
文摘The immediate priorities for high-power delivery employing solid-core fibers are balancing the nonlinear effect and beam deterioration.Here,the scheme of tapered multimode fiber is experimentally realized.The tapered multimode fiber,featuring a 15 m(24/200μm)–10 m(tapered region)–80 m(48/400μm)profile,guides the laser with a weakly coupled condition.With the input power of 1035 W,the maximum output power over the 105 m delivery is 962 W,corresponding to a high efficiency of over 93%and a nonlinear suppression ratio of over 50 dB.Mode resolving results show high-order-mode contents of less than–30 dB in the whole delivery path,resulting in a high-fidelity delivery with M2 factors of 1.20 and 1.23 for the input and output lasers,respectively.Furthermore,the ultimate limits of delivery lengths for solid-core weakly coupled fibers are discussed.This work provides a valuable reference to reconsider the future boom of high-power laser delivery based on solid-core fibers.
基金supported by the Shanghai Municipal Natural Science Foundation(Grant No.20ZR1464500)the National Natural Science Foundation of China(NSFC)(Grant Nos.61905257 and U1930115)+1 种基金the Shanghai Municipal Science and Technology Major Project(Grant No.2017SHZDZX02)the Ministry of Science and Higher Education of the Russian Federation(Project No.FFUF-2024-0038)。
文摘Spatial intensity modulation in amplified laser beams,particularly hot spots,critically constrains attainable pulse peak power due to the damage threshold limitations of four-grating compressors.This study demonstrates that the double-smoothing grating compressor(DSGC)configuration effectively suppresses modulation through directional beam smoothing.Our systematic investigation validated the double-smoothing effect through numerical simulations and experimental measurements,with comprehensive spatiotemporal analysis revealing excellent agreement between numerical and practical pulse characteristics.Crucially,the DSGC enables a 1.74 times energy output boost compared to conventional compressors.These findings establish the DSGC as a pivotal advancement for next-generation ultrahighpower laser systems,providing a viable pathway toward hundreds of PW output through optimized spatial energy redistribution.
基金supported by the National Natural Science Foundation of China(NSFC)(12074399,12204500 and 12004403)the Key Projects of Intergovernmental International Scientific and Technological Innovation Cooperation(2021YFE0116700)+1 种基金the Shanghai Natural Science Foundation(20ZR1464400)the Shanghai Sailing Program(22YF1455300).
文摘Laser-driven inertial confinement fusion(ICF)diagnostics play a crucial role in understanding the complex physical processes governing ICF and enabling ignition.During the ICF process,the interaction between the high-power laser and ablation material leads to the formation of a plasma critical surface,which reflects a significant portion of the driving laser,reducing the efficiency of laser energy conversion into implosive kinetic energy.Effective diagnostic methods for the critical surface remain elusive.In this work,we propose a novel optical diagnostic approach to investigate the plasma critical surface.This method has been experimentally validated,providing new insights into the critical surface morphology and dynamics.This advancement represents a significant step forward in ICF diagnostic capabilities,with the potential to inform strategies for enhancing the uniformity of the driving laser and target surface,ultimately improving the efficiency of converting laser energy into implosion kinetic energy and enabling ignition.
基金supported by the National Natural Science Foundation of China(Grant Nos.12204499 and 12174212)the Joint Key Projects of National Natural Science Foundation of China(Grant No.U2032206)。
文摘This paper presents an investigation of the secondary saturation characteristics of a HfTe_(2)saturable absorber.Pulse energies of 5.85 and 7.4 mJ were demonstrated with a high-order Hermite-Gaussian(HG)laser and a vortex laser,respectively,using alexandrite as the gain medium.To the best of our knowledge,these are the highest pulse energies directly generated with HG and vortex lasers.To broaden the applications of high-energy pulsed HG and vortex lasers,wavelength tuning in the region of 40 nm was achieved using an etalon.pulse energy of 5.85 mJ and a vortex laser with a single pulse energy of 7.4 mJ were obtained in alexandrite.The repetition rates of these lasers were 262 and 196 Hz,respectively.To expand the applications of high-energy structured lasers,wavelength tuning within the range of 747-787 nm was successfully accomplished using an etalon.
基金support by DASHH(Data Science in Hamburg-Helmholtz Graduate School for the Structure of Matter)with grant No.HIDSS-0002。
文摘This study investigates the influence of seismic activities on the optical synchronization system of the European X-ray Free-Electron Laser.We analyze the controller input/output data of phase-locked loops in length-stabilized links,focusing on the response to earthquakes,ocean-generated microseism and civilization noise.By comparing the controller data with external data,we were able to identify disturbances and their effects on the control signals.Our results show that seismic events influence the stability of the phase-locked loops.Even earthquakes that are approximately 5000 km away cause remarkable fluctuations in the in-loop control signals.Ocean-generated microseism in particular has an enormous influence on the in-loop control signals due to its constant presence.The optical synchronization system is so highly sensitive that it can even identify vibrations caused by civilization,such as road traffic or major events like concerts or sport events.The phase-locked loops manage to eliminate more than 99%of the existing interference.
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(Grant Nos.12375244,12305265,12135009 and 12174047)the Natural Science Foundation of Hunan Province of China(Grant No.2025JJ30002)。
文摘With the escalating laser peak power,modulating and detecting the intensity,duration,phase and polarization of ultraintense laser pulses progressively becomes increasingly arduous due to the limited damage thresholds of conventional optical components.In particular,the generation and detection of ultra-intense vortex lasers pose great challenges for current laser technologies,which has limited the widely potential applications of relativistic vortex lasers in various domains.In this study,we propose to reconstruct the vortex phase and generate and amplify the relativistic vortex lasers via surface plasma holograms(SPHs).By interfering with the object laser and reference laser,SPHs are formed on the target and the phase of the interfering laser is imprinted through the modulation of surface plasma density.In particular,using the quadrature phase-shift interference,the vortex phase of the object laser can be well reconstructed.The generated vortex lasers can be focused and enhanced further by one order of magnitude,up to 1.7×10^(21)W/cm^(2),which has been demonstrated by full three-dimensional particle-in-cell simulations.For the first time,we provide a practical way to detect the phase of relativistic vortex lasers,which can be applied in large 1–10 PW laser facilities.This will promote future experimental research of vortex-laser–plasma interaction and open a new avenue of plasma optics in the ultra-relativistic regime.
基金supported by the Key Projects of Intergovernmental International Scientific and Technological Innovation Cooperation(Grant No.2021YFE0116700)the National Natural Science Foundation of China(NSFC)(Grant Nos.12204500 and 12074399)+1 种基金the Shanghai Sailing Program(Grant No.22YF1455300)the Chinese Academy of Sciences(Grant Nos.XDA25020105,XDA25020103 and XDA25020101)。
文摘Coherent combining of several low-energy few-cycle beams offers a reliable and feasible approach to producing fewcycle laser pulses with energies exceeding the multi-joule level.However,time synchronization and carrier-envelope phase difference(ΔCEP)between pulses significantly affect the temporal waveform and intensity of the combined pulse,requiring precise measurement and control.Here,we propose a concise optical method based on the phase retrieval of spectral interference and quadratic function symmetry axis fitting to simultaneously measure the time synchronization andΔCEP between few-cycle pulses.The control precision of our coherent beam combining system can achieve a time delay stability within 42 as andΔCEP measurement precision of 40 mrad,enabling a maximum combining efficiency of 98.5%.This method can effectively improve the performance and stability of coherent beam combining systems for few-cycle lasers,which will facilitate the obtaining of high-quality few-cycle lasers with high energy.
基金supported by the National Natural Science Foundation of China(Grant Nos.12175310,12275356,12135009 and 12075157)the Natural Science Foundation of Hunan Province(Grant No.2022JJ20042)。
文摘The propagation of multiple ultraintense femtosecond lasers in underdense plasmas is investigated theoretically and numerically.We find that the energy merging effect between two in-phase seed lasers can be improved by using two obliquely incident guiding lasers whose initial phase isπandπ/2 ahead of the seed laser.Particle-in-cell simulations show that due to the repulsion and energy transfer of the guiding laser,the peak intensity of the merged light is amplified by more than five times compared to the seed laser.The energy conversion efficiency from all incident lasers to the merged light is up to approximately 60%.The results are useful for many applications,including plasma-based optical amplification,charged particle acceleration and extremely intense magnetic field generation.
基金supported by the National Natural Science Foundation of China(Grant Nos.12175310,12275356,12305268,12105362,12375244,12135009 and U22411281)the Natural Science Foundation of Hunan Province(Grant Nos.2021JJ40653,2020JJ5031 and 2025JJ30002)+1 种基金the Scientific Research Foundation of the Hunan Provincial Education Department(Grant No.22B0655)the Hunan Provincial Innovation Foundation for Postgraduates(Grant No.CX20210006)。
文摘The effect of the polarizations of two counter-propagating relativistic laser pulses interacting with subwavelength thin solid-density foil is investigated.Three-dimensional particle-in-cell simulations and analytical modelling show that the interaction and resulting transverse instability depend strongly on the polarization directions as well as the intensity distribution of the resultant light field in the foil.The left-and right-handed circularly polarized laser pair with the same phase at the common focal spot in the ultrathin foil leads to the strongest distortion of the foil.The fastest growing mode and maximum growth rate depend mainly on the laser intensity.For all polarization and phase-difference combinations,the instability is weakest when the two laser pulses are exactly out of phase at the common focusing point in the foil.
基金supported by the National Natural Science Foundation of China(Grant Nos.62465006 and 61975168).
文摘In this work,we confirm a Pr^(3+):LiYF_(4)pulsed laser with high power and high energy at 639 nm based on the acoustooptic cavity dumping technique.The maximum average output power,narrowest pulse width,highest pulse energy and peak power of the pulsed laser at a repetition rate of 0.1 kHz are 532 mW,112 ns,5.32 mJ and 47.5 kW,respectively.A 639 nm pulsed laser with such high pulse energy and peak power has not been reported previously.Furthermore,we obtain a widely tunable range of repetition rates from 0.1 to 5000 kHz.The diffracted beam quality factors M^(2) are 2.18(in the x direction)and 2.04(in the y direction).To the best of our knowledge,this is the first time that a cavity-dumped all-solid-state pulsed laser in the visible band has been reported.This work provides a promising method for obtaining high-performance pulsed lasers.
