title: Mid-infrared laser-driven broadband water-window supercontinuum generation from pre-excited medium.
abstract: We theoretically investigate the broadband water-window supercontinuum generation from pre-excited medium with a mid-infrared pulse. We find that the wavelength scaling of the harmonic yield from near-visible (0.8 μm) to mid-infrared (1.8 μm) in single-atom level is λ(-2.7). Using an intense phase-stabilized few-cycle 1.6 μm laser pulse, a broadband water window supercontinuum with bandwidth of approximately 140 eV is obtained. We also investigate the macroscopic effects and find that large initial population of the excited state leads to the high-density of free electrons, which shift the carrier-envelop phase of the driving pulse and further diminish the water-window supercontinuum generation. The highly-ionized medium also results in poor temporal and spatial properties of the attosecond pulse. Instead, small initial population of the excited state can produce well phase-matched xuv supercontinuum in water-window region and an 100-as pulse with central wavelength of 2.8 nm and pulse energy of 0.15 nJ can be filtered out.
authors: Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China.
authors: Yang
authors: Y
authors: Li
authors: Weiyi
authors: W
authors: Hong
authors: Qingbin
authors: Q
authors: Zhang
authors: Shaoyi
authors: S
authors: Wang
authors: Peixiang
authors: P
authors: Lu
mesh_terms: D003198:Computer Simulation; D007259:Infrared Rays; D007834:Lasers; D008027:Light; D008962:Models, Theoretical; D012542:Scattering, Radiation; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water