Broadband frequency-tripling pulses with high energy are attractive for scientific research,such as inertial confinement fusion,but are difficult to scale up.Third-harmonic generation via nonlinear frequency conversio...Broadband frequency-tripling pulses with high energy are attractive for scientific research,such as inertial confinement fusion,but are difficult to scale up.Third-harmonic generation via nonlinear frequency conversion,however,remains a trade-off between bandwidth and conversion efficiency.Based on gradient deuterium deuterated potassium dihydrogen phosphate(KD_(x)H_(2-x)PO_(4),DKDP)crystal,here we report the generation of frequency-tripling pulses by rapid adiabatic passage with a low-coherence laser driver facility.The efficiency dependence on the phase-matching angle in a Type-II configuration is studied.We attained an output at 352 nm with a bandwidth of 4.4 THz and an efficiency of 36%.These results,to the best of our knowledge,represent the first experimental demonstration of gradient deuterium DKDP crystal in obtaining frequency-tripling pulses.Our research paves a new way for developing high-efficiency,large-bandwidth frequency-tripling technology.展开更多
In this review,we introduce the progress in the growth of large-aperture DKDP crystals and some aspects of crystal quality including determination of deuterium content,homogeneity of deuterium distribution,residual st...In this review,we introduce the progress in the growth of large-aperture DKDP crystals and some aspects of crystal quality including determination of deuterium content,homogeneity of deuterium distribution,residual strains,nonlinear absorption,and laser-induced damage resistance for its application in high power laser system.Large-aperture high-quality DKDP crystal with deuteration level of 70%has been successfully grown by the traditional method,which can fabricate the large single-crystal optics with the size exceeding 400 mm.Neutron diffraction technique is an efficient method to research the deuterium content and 3D residual strains in single crystals.More efforts have been paid in the processes of purity of raw materials,continuous filtration technology,thermal annealing and laser conditioning for increasing the laser-induced damage threshold(LIDT)and these processes enable the currently grown crystals to meet the specifications of the laser system for inertial confinement fusion(ICF),although the laser damage mechanism and laser conditioning mechanism are still not well understood.The advancements on growth of large-aperture high-quality DKDP crystal would support the development of ICF in China.展开更多
基金supported by the President Funding Independent Project of the China Academy of Engineering Physics(No.YZJJZL2024200)the National Natural Science Foundation of China(No.62405298)the National Key Research and Development Program of China(No.2023YFA1608503).
文摘Broadband frequency-tripling pulses with high energy are attractive for scientific research,such as inertial confinement fusion,but are difficult to scale up.Third-harmonic generation via nonlinear frequency conversion,however,remains a trade-off between bandwidth and conversion efficiency.Based on gradient deuterium deuterated potassium dihydrogen phosphate(KD_(x)H_(2-x)PO_(4),DKDP)crystal,here we report the generation of frequency-tripling pulses by rapid adiabatic passage with a low-coherence laser driver facility.The efficiency dependence on the phase-matching angle in a Type-II configuration is studied.We attained an output at 352 nm with a bandwidth of 4.4 THz and an efficiency of 36%.These results,to the best of our knowledge,represent the first experimental demonstration of gradient deuterium DKDP crystal in obtaining frequency-tripling pulses.Our research paves a new way for developing high-efficiency,large-bandwidth frequency-tripling technology.
基金supported part by the Young Scholars Program of Shandong University(GrantNo.2018WUH65)and theFundamental ResearchFundsof the Central Universities.The authors also thank the support of neutron diffraction technique from Institute of Nuclear Physics and Chemistry,China Academyof Engineering Physics.
文摘In this review,we introduce the progress in the growth of large-aperture DKDP crystals and some aspects of crystal quality including determination of deuterium content,homogeneity of deuterium distribution,residual strains,nonlinear absorption,and laser-induced damage resistance for its application in high power laser system.Large-aperture high-quality DKDP crystal with deuteration level of 70%has been successfully grown by the traditional method,which can fabricate the large single-crystal optics with the size exceeding 400 mm.Neutron diffraction technique is an efficient method to research the deuterium content and 3D residual strains in single crystals.More efforts have been paid in the processes of purity of raw materials,continuous filtration technology,thermal annealing and laser conditioning for increasing the laser-induced damage threshold(LIDT)and these processes enable the currently grown crystals to meet the specifications of the laser system for inertial confinement fusion(ICF),although the laser damage mechanism and laser conditioning mechanism are still not well understood.The advancements on growth of large-aperture high-quality DKDP crystal would support the development of ICF in China.
