Generation of an isolated sub-100 attosecond pulse in the water-window spectral region

作者：Pu Zou, Ruxin Li, Zeng Zhi-Nan, Xiong Hui, Peng Liu, Leng Yu-Xin, FAN PIN-ZHONG, Zhizhan Xu · 发表于：Chinese Physics B · 年份：2010 · DOI：10.1088/1674-1056/19/1/019501 · 被引用次数：11 · 研究领域：Laser-Matter Interactions and Applications、Spectroscopy and Quantum Chemical Studies、Mass Spectrometry Techniques and Applications

We propose a scheme to generate isolated attosecond pulses in the water-window spectral region. Based on the numerical solutions of the single active electron model, we investigate high-order harmonic generation in helium atoms driven by a multi-cycle two-colour optical field synthesized by an intense 2000 nm, 20 fs pulse and its frequency-doubled pulse. When the latter is slightly detuned and properly phase shifted with respect to the fundamental laser pulse, an ultra-broad extreme ultraviolet supercontinuum with a spectral width of 130 eV can be generated in the 270–400 eV spectral regions. A supercontinuum from 280–340 eV in the water window can be selected to yield an isolated 67 attosecond pulse without employing any phase compensation. This water window coherent x-ray pulse with less than 100 attosecond duration is a potential tool for studying the ultrafast electronic dynamics of biological samples in water.