Here,we report the recent progress on the front end developed for the 100 PW-class laser facility.Using 3 stages of optical parametric chirped-pulse amplification(OPCPA)based on lithium triborate(LBO)crystals,we reali...Here,we report the recent progress on the front end developed for the 100 PW-class laser facility.Using 3 stages of optical parametric chirped-pulse amplification(OPCPA)based on lithium triborate(LBO)crystals,we realized a 5.26 J/0.1 Hz amplified output with a bandwidth over 200 nm near the center wavelength of 925 nm.After the compressor,we obtained a pulse duration of 13.4 fs.As the compression efficiency reached 67%,this OPCPA front end could potentially support a peak power of 263 TW at a repetition rate of 0.1 Hz.To the best of our knowledge,among all the 100 TW-level OPCPA systems,it shows the widest spectral width,the shortest pulse duration,and it is also the first OPCPA system working at a repetition-rate mode.展开更多
High-power femtosecond lasers beyond 5μm are attractive for strong-field physics with mid-infrared(IR)fields but are difficult to scale up.In optical parametric chirped-pulse amplification(OPCPA)at mid-IR wavelengths...High-power femtosecond lasers beyond 5μm are attractive for strong-field physics with mid-infrared(IR)fields but are difficult to scale up.In optical parametric chirped-pulse amplification(OPCPA)at mid-IR wavelengths,a nonlinear crystal is vital,and its transmittance,dispersion,nonlinear coefficient and size determine the achievable power and wavelength.OPCPA beyond 5μm routinely relies on semiconductor crystals because common oxide crystals are not transparent in this spectral range.However,the small size and low damage threshold of semiconductor crystals fundamentally limit the peak power to gigawatts.In this paper,we design a terawatt-class OPCPA system at 5.2μm based on a new kind of oxide crystal of La3Ga5.5Nb0.5O14(LGN).The extended transparent range,high damage threshold,superior phase-matching characteristics and large size of LGN enable the generation of 0.13 TW seven-cycle pulses at5.2μm.This design fully relies on the state-of-the-art OPCPA technology of an octave-spanning ultrafast Ti:sapphire laser and a thin-disk Yb:YAG laser,offering the performance characteristics of high power,a high repetition rate and a stable carrier-envelope phase.展开更多
The Z-backlighter laser facility primarily consists of two high energy, high-power laser systems. Z-Beamlet laser(ZBL)(Rambo et al., Appl. Opt. 44, 2421(2005)) is a multi-kJ-class, nanosecond laser operating at 1054 n...The Z-backlighter laser facility primarily consists of two high energy, high-power laser systems. Z-Beamlet laser(ZBL)(Rambo et al., Appl. Opt. 44, 2421(2005)) is a multi-kJ-class, nanosecond laser operating at 1054 nm which is frequency doubled to 527 nm in order to provide x-ray backlighting of high energy density events on the Z-machine. Z-Petawatt(ZPW)(Schwarz et al., J. Phys.: Conf. Ser. 112, 032020(2008)) is a petawatt-class system operating at 1054 nm delivering up to 500 J in 500 fs for backlighting and various short-pulse laser experiments(see also Figure 10 for a facility overview). With the development of the magnetized liner inertial fusion(MagLIF) concept on the Z-machine, the primary backlighting missions of ZBL and ZPW have been adjusted accordingly. As a result, we have focused our recent efforts on increasing the output energy of ZBL from 2 to 4 kJ at 527 nm by modifying the fiber front end to now include extra bandwidth(for stimulated Brillouin scattering suppression). The MagLIF concept requires a well-defined/behaved beam for interaction with the pressurized fuel. Hence we have made great efforts to implement an adaptive optics system on ZBL and have explored the use of phase plates. We are also exploring concepts to use ZPW as a backlighter for ZBL driven MagLIF experiments. Alternatively, ZPW could be used as an additional fusion fuel pre-heater or as a temporally flexible high energy pre-pulse. All of these concepts require the ability to operate the ZPW in a nanosecond long-pulse mode, in which the beam can co-propagate with ZBL. Some of the proposed modifications are complete and most of them are well on their way.展开更多
基金Shanghai Municipal Science and Technology Major Project(2017SHZDZX02)Natural Science Foundation of Shanghai(20ZR1464600)+5 种基金This work is funded by the National Key R&D Program of China(2017YFE0123700)Program of Shanghai Academic/Technology Research Leader(18XD1404200)and International Partnership Program of Chinese Academy of Sciences(181231KYSB20200040)Shanghai Sailing Program(19YF1453100)National Natural Science Foundation of China(61925507)Youth Innovation Promotion Association of the Chinese Academy of Sciences The Strategic Priority Research Program of the Chinese Academy of Sciences(XDB1603)。
文摘Here,we report the recent progress on the front end developed for the 100 PW-class laser facility.Using 3 stages of optical parametric chirped-pulse amplification(OPCPA)based on lithium triborate(LBO)crystals,we realized a 5.26 J/0.1 Hz amplified output with a bandwidth over 200 nm near the center wavelength of 925 nm.After the compressor,we obtained a pulse duration of 13.4 fs.As the compression efficiency reached 67%,this OPCPA front end could potentially support a peak power of 263 TW at a repetition rate of 0.1 Hz.To the best of our knowledge,among all the 100 TW-level OPCPA systems,it shows the widest spectral width,the shortest pulse duration,and it is also the first OPCPA system working at a repetition-rate mode.
基金supported in part by the National Natural Science Foundation of China(Nos.6170512861727820 and 91850203)Science and Technology Commission of Shanghai Municipality(Nos.17YF1409100 and17ZR1414000)。
文摘High-power femtosecond lasers beyond 5μm are attractive for strong-field physics with mid-infrared(IR)fields but are difficult to scale up.In optical parametric chirped-pulse amplification(OPCPA)at mid-IR wavelengths,a nonlinear crystal is vital,and its transmittance,dispersion,nonlinear coefficient and size determine the achievable power and wavelength.OPCPA beyond 5μm routinely relies on semiconductor crystals because common oxide crystals are not transparent in this spectral range.However,the small size and low damage threshold of semiconductor crystals fundamentally limit the peak power to gigawatts.In this paper,we design a terawatt-class OPCPA system at 5.2μm based on a new kind of oxide crystal of La3Ga5.5Nb0.5O14(LGN).The extended transparent range,high damage threshold,superior phase-matching characteristics and large size of LGN enable the generation of 0.13 TW seven-cycle pulses at5.2μm.This design fully relies on the state-of-the-art OPCPA technology of an octave-spanning ultrafast Ti:sapphire laser and a thin-disk Yb:YAG laser,offering the performance characteristics of high power,a high repetition rate and a stable carrier-envelope phase.
文摘The Z-backlighter laser facility primarily consists of two high energy, high-power laser systems. Z-Beamlet laser(ZBL)(Rambo et al., Appl. Opt. 44, 2421(2005)) is a multi-kJ-class, nanosecond laser operating at 1054 nm which is frequency doubled to 527 nm in order to provide x-ray backlighting of high energy density events on the Z-machine. Z-Petawatt(ZPW)(Schwarz et al., J. Phys.: Conf. Ser. 112, 032020(2008)) is a petawatt-class system operating at 1054 nm delivering up to 500 J in 500 fs for backlighting and various short-pulse laser experiments(see also Figure 10 for a facility overview). With the development of the magnetized liner inertial fusion(MagLIF) concept on the Z-machine, the primary backlighting missions of ZBL and ZPW have been adjusted accordingly. As a result, we have focused our recent efforts on increasing the output energy of ZBL from 2 to 4 kJ at 527 nm by modifying the fiber front end to now include extra bandwidth(for stimulated Brillouin scattering suppression). The MagLIF concept requires a well-defined/behaved beam for interaction with the pressurized fuel. Hence we have made great efforts to implement an adaptive optics system on ZBL and have explored the use of phase plates. We are also exploring concepts to use ZPW as a backlighter for ZBL driven MagLIF experiments. Alternatively, ZPW could be used as an additional fusion fuel pre-heater or as a temporally flexible high energy pre-pulse. All of these concepts require the ability to operate the ZPW in a nanosecond long-pulse mode, in which the beam can co-propagate with ZBL. Some of the proposed modifications are complete and most of them are well on their way.
