Saito Nariyuki, Ishii Nobuhisa, Kanai Teruto, Watanabe Shuntaro, Itatani Jiro
The Institute for Solid State Physics, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8581, Japan.
Research Institute for Science and Technology, Tokyo University of Science, Yamasaki 2641, Noda, Chiba 278-8510, Japan.
Sci Rep. 2016 Oct 18;6:35594. doi: 10.1038/srep35594.
Long-wavelength lasers have great potential to become a new-generation drive laser for tabletop coherent light sources in the soft X-ray region. Because of the significantly low conversion efficiency from a long-wavelength light field to high-order harmonics, their pulse characterization has been carried out by measuring the carrier-envelope phase and/or spatial dependences of high harmonic spectra. However, these photon detection schemes, in general, have difficulty in obtaining information on the spectral phases, which is crucial to determine the temporal structures of high-order harmonics. Here, we report the first attosecond streaking measurement of high harmonics generated by few-cycle optical pulses at 1.7 μm from a BiBO-based optical parametric chirped-pulse amplifier. This is also the first demonstration of time-resolved photoelectron spectroscopy using high harmonics from a long-wavelength drive laser other than Ti:sapphire lasers, which paves the way towards ultrafast soft X-ray photoelectron spectroscopy.
长波长激光有很大潜力成为用于软X射线区域桌面相干光源的新一代驱动激光。由于从长波长光场到高次谐波的转换效率显著较低，它们的脉冲特性是通过测量高次谐波光谱的载波包络相位和/或空间依赖性来进行的。然而，一般来说，这些光子探测方案在获取光谱相位信息方面存在困难，而光谱相位信息对于确定高次谐波的时间结构至关重要。在此，我们报告了首次对基于BiBO的光参量啁啾脉冲放大器产生的1.7μm少周期光脉冲产生的高次谐波进行的阿秒条纹测量。这也是首次展示使用除钛宝石激光器之外的长波长驱动激光产生的高次谐波进行时间分辨光电子能谱，这为超快软X射线光电子能谱铺平了道路。
