Ultraintense short-period infrared laser pulses play an important role in frontier scientific research,but their power is quite low when generated using current technology.This paper demonstrates a scheme for generati...Ultraintense short-period infrared laser pulses play an important role in frontier scientific research,but their power is quite low when generated using current technology.This paper demonstrates a scheme for generating an ultraintense few-cycle infrared pulse by directly compressing a long infrared pulse.In this scheme,an infrared picosecond-to-nanosecond laser pulse counterpropagates with a rapidly extending plasma grating that is created by ionizing an undulated gas by a short laser pulse,and the infrared laser pulse is reflected by the rapidly extending plasma grating.Because of the high expansion velocity of the latter,the infrared laser pulse is compressed in the reflection process.One-and two-dimensional particle-in-cell simulations show that by this method,a pulse with a duration of tens of picoseconds in the mid-to far-infrared range can be compressed to a few cycles with an efficiency exceeding 60%,thereby making ultraintense few-cycle infrared pulses possible.展开更多
A method is proposed for compressing laser pulses by fast-extending plasma gratings(FEPGs),which are created by ionizing a hypersonic wave generated by stimulated Brillouin scattering in a background gas.Ionized by a ...A method is proposed for compressing laser pulses by fast-extending plasma gratings(FEPGs),which are created by ionizing a hypersonic wave generated by stimulated Brillouin scattering in a background gas.Ionized by a short laser pulse,the phonon forms a light-velocity FEPG to fully reflect a resonant pump laser.As the reflecting surface moves with the velocity of light,the reflected pulse is temporally overlapped and compressed.One-and two-dimensional fully kinetic particle-in-cell simulations with a laser wavelength of 1μm show that in this regime,a pump pulse is compressed from 10–40 ps to 7–10 fs(i.e.,a few optical cycles),with a two-dimensional transfer efficiency up to 60%.This method is a promising way to produce critical laser powers while avoiding several significant problems that arise in plasma-based compressors,including an unwanted linear stage,major plasma instabilities,and the need for seed preparation.展开更多
The results of a commissioning experiment on the SILEX-Ⅱlaser facility(formerly known as CAEP-PW)are reported.SILEX-Ⅱis a complete optical parametric chirped-pulse amplification laser facility.The peak power reached...The results of a commissioning experiment on the SILEX-Ⅱlaser facility(formerly known as CAEP-PW)are reported.SILEX-Ⅱis a complete optical parametric chirped-pulse amplification laser facility.The peak power reached about 1 PWin a 30 fs pulse duration during the experiment.The laser contrast was better than 1010 at 20 ps ahead of the main pulse.In the basic laser foil target interaction,a set of experimental data were collected,including spatially resolved x-ray emission,the image of the coherent transition radiation,the harmonic spectra in the direction of reflection,the energy spectra and beam profile of accelerated protons,hot-electron spectra,and transmitted laser energy fraction and spatial distribution.The experimental results show that the laser intensity reached 531020 W/cm^(2) within a 5.8μm focus(FWHM).Significant laser transmission did not occur when the thickness of theCHfoil was equal to or greater than 50 nm.The maximum energy of the accelerated protons in the target normal direction was roughly unchanged when the target thickness varied between 50 nm and 15μm.The maximum proton energy via the target normal sheath field acceleration mechanism was about 21 MeV.We expect the on-target laser intensity to reach 10^(22) W/cm^(2) in the near future,after optimization of the laser focus and upgrade of the laser power to 3 PW.展开更多
A cylindricalÖffner stretcher based on ternary reflector(COSTER)is proposed and analyzed.Compared with the traditionalÖffner stretcher,the COSTER has no off-axis aberration in the multipass configuration,and...A cylindricalÖffner stretcher based on ternary reflector(COSTER)is proposed and analyzed.Compared with the traditionalÖffner stretcher,the COSTER has no off-axis aberration in the multipass configuration,and the output laser of COSTER has lower spectral phase noise and higher temporal contrast in the far field.The COSTER is quite suitable to be used in multipetawatt laser facilities,and it might be the preferred stretcher configuration for ultrafast and ultra-intense lasers.展开更多
Femtosecond lasers are powerful in studying matter's ultrafast dynamics within femtosecond to attosecond time scales.Drawing a three-dimensional(3D)topological map of the optical field of a femtosecond laser pulse...Femtosecond lasers are powerful in studying matter's ultrafast dynamics within femtosecond to attosecond time scales.Drawing a three-dimensional(3D)topological map of the optical field of a femtosecond laser pulse including its spatiotemporal amplitude and phase distributions,allows one to predict and understand the underlying physics of light interaction with matter,whose spatially resolved transient dielectric function experiences ultrafast evolution.However,such a task is technically challenging for two reasons:first,one has to capture in single-shot and squeeze the 3D information of an optical field profile into a two-dimensional(2D)detector;second,typical detectors are only sensitive to intensity or amplitude information rather than phase.Here we have demonstrated compressed optical field topography(COFT)drawing a 3D map for an ultrafast optical field in single-shot,by combining the coded aperture snapshot spectral imaging(CASSI)technique with a global 3D phase retrieval procedure.COFT can,in single-shot,fully characterize the spatiotemporal coupling of a femtosecond laser pulse,and live stream the light-speed propagation of an air plasma ionization front,unveiling its potential applications in ultrafast sciences.展开更多
基金China Academy of Engineering Physics(Grant No.CX20200022)the National Key Program for S&T Research and Development(Grant No.2018YFA0404804)the National Natural Science Foundation of China(Grant No.11875240).
文摘Ultraintense short-period infrared laser pulses play an important role in frontier scientific research,but their power is quite low when generated using current technology.This paper demonstrates a scheme for generating an ultraintense few-cycle infrared pulse by directly compressing a long infrared pulse.In this scheme,an infrared picosecond-to-nanosecond laser pulse counterpropagates with a rapidly extending plasma grating that is created by ionizing an undulated gas by a short laser pulse,and the infrared laser pulse is reflected by the rapidly extending plasma grating.Because of the high expansion velocity of the latter,the infrared laser pulse is compressed in the reflection process.One-and two-dimensional particle-in-cell simulations show that by this method,a pulse with a duration of tens of picoseconds in the mid-to far-infrared range can be compressed to a few cycles with an efficiency exceeding 60%,thereby making ultraintense few-cycle infrared pulses possible.
基金This work was partly supported by the National Key Program for S&T Research and Development(Grant No.2018YFA0404804)the National Natural Science Foundation of China(Grant No.11875240)the Science and Technology on Plasma Physics Laboratory Fund(Grant No.6142A0403010417).
文摘A method is proposed for compressing laser pulses by fast-extending plasma gratings(FEPGs),which are created by ionizing a hypersonic wave generated by stimulated Brillouin scattering in a background gas.Ionized by a short laser pulse,the phonon forms a light-velocity FEPG to fully reflect a resonant pump laser.As the reflecting surface moves with the velocity of light,the reflected pulse is temporally overlapped and compressed.One-and two-dimensional fully kinetic particle-in-cell simulations with a laser wavelength of 1μm show that in this regime,a pump pulse is compressed from 10–40 ps to 7–10 fs(i.e.,a few optical cycles),with a two-dimensional transfer efficiency up to 60%.This method is a promising way to produce critical laser powers while avoiding several significant problems that arise in plasma-based compressors,including an unwanted linear stage,major plasma instabilities,and the need for seed preparation.
基金This work was supported by the National Key Program for S&T Research and Development(Grant No.2018YFA0404804)the Science Challenge Project(Grant No.TZ2016005)the National Natural Science Foundation of China(Grant No.11805181).
文摘The results of a commissioning experiment on the SILEX-Ⅱlaser facility(formerly known as CAEP-PW)are reported.SILEX-Ⅱis a complete optical parametric chirped-pulse amplification laser facility.The peak power reached about 1 PWin a 30 fs pulse duration during the experiment.The laser contrast was better than 1010 at 20 ps ahead of the main pulse.In the basic laser foil target interaction,a set of experimental data were collected,including spatially resolved x-ray emission,the image of the coherent transition radiation,the harmonic spectra in the direction of reflection,the energy spectra and beam profile of accelerated protons,hot-electron spectra,and transmitted laser energy fraction and spatial distribution.The experimental results show that the laser intensity reached 531020 W/cm^(2) within a 5.8μm focus(FWHM).Significant laser transmission did not occur when the thickness of theCHfoil was equal to or greater than 50 nm.The maximum energy of the accelerated protons in the target normal direction was roughly unchanged when the target thickness varied between 50 nm and 15μm.The maximum proton energy via the target normal sheath field acceleration mechanism was about 21 MeV.We expect the on-target laser intensity to reach 10^(22) W/cm^(2) in the near future,after optimization of the laser focus and upgrade of the laser power to 3 PW.
基金supported by the Innovation and Development Foundation of China Academy of Engineering Physics(No.CX20200022)the Science and Technology on Plasma Physics Laboratory Independent Research Projects of China Academy of Engineering Physics(No.JCKYS2022212004)。
文摘A cylindricalÖffner stretcher based on ternary reflector(COSTER)is proposed and analyzed.Compared with the traditionalÖffner stretcher,the COSTER has no off-axis aberration in the multipass configuration,and the output laser of COSTER has lower spectral phase noise and higher temporal contrast in the far field.The COSTER is quite suitable to be used in multipetawatt laser facilities,and it might be the preferred stretcher configuration for ultrafast and ultra-intense lasers.
基金supportedby the National Natural Science Foundation of China(Grant No.11875140),Science and Technology on Plasma Physics Laboratory(Grant No.6142A04200212)Innovation Project of Optics Valley Laboratory(Grant No.OVL2021ZD001),and Innovation Fund of WNLO.
文摘Femtosecond lasers are powerful in studying matter's ultrafast dynamics within femtosecond to attosecond time scales.Drawing a three-dimensional(3D)topological map of the optical field of a femtosecond laser pulse including its spatiotemporal amplitude and phase distributions,allows one to predict and understand the underlying physics of light interaction with matter,whose spatially resolved transient dielectric function experiences ultrafast evolution.However,such a task is technically challenging for two reasons:first,one has to capture in single-shot and squeeze the 3D information of an optical field profile into a two-dimensional(2D)detector;second,typical detectors are only sensitive to intensity or amplitude information rather than phase.Here we have demonstrated compressed optical field topography(COFT)drawing a 3D map for an ultrafast optical field in single-shot,by combining the coded aperture snapshot spectral imaging(CASSI)technique with a global 3D phase retrieval procedure.COFT can,in single-shot,fully characterize the spatiotemporal coupling of a femtosecond laser pulse,and live stream the light-speed propagation of an air plasma ionization front,unveiling its potential applications in ultrafast sciences.