Generation of intense isolated attosecond pulses for attosecond nonlinear opitcs

我们已经产生了高能量的孤立阿秒脉冲，其强度足以诱导原子和分子中的非线性现象。利用氮气分子中双光子双电离的自相关测量，直接表征了脉冲宽度。通过精心设计产生结构，我们获得了能量高达1.3微焦耳/脉冲的孤立阿秒脉冲，与之前的报道相比，其能量提高了100-1000倍。根据自相关方法确定的500As脉冲宽度，这个孤立的阿秒脉冲的峰值功率估计为2.6GW。该方法为密集阿秒科学前沿铺平了道路，必将带来超快现象和非线性光学研究的一大飞跃。

We have generated high energy isolated attosecond pulses, which are intense enough to induce the nonlinear phenomena in atoms and molecules. The pulse width was direct characterized by autocorrelation measurement based on two-photon double ionization in nitrogen molecules. By carefully designing the generation configurations, we obtained isolated attosecond pulses with energy up to 1.3 micro Joule/pulse, thus showing its energy enhancement from 100- to 1000-fold compared with the previous report so far. From a 500-as pulse duration determined by the autocorrelation method, the peak power of this isolated attosecond pulse was evaluated to be 2.6 GW. The presented method paves the way for the intense attosecond science frontier, which will certainly bring a great leap forward in research on ultrafast phenomena and nonlinear optics.