We theoretically study the high-order harmonics and single attosecond pulse generation from a pre-excited He⁺ ion in a multicycle two-color spatially inhomogeneous field. It is shown that the broadband supercontinuum spectrum and single quantum path selection can be realized, and then a single 15.2 as pulse is directly obtained. By appending a uv attosecond pulse to the two-color spatially inhomogeneous field at a proper time, the conversion efficiency of the high-energy part of the supercontinuum is improved by at least an order of magnitude, which enables the production of an intense single 17.3 as pulse.

中文翻译：

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具有多周期空间不均匀场的强单个短阿秒脉冲的产生

我们从理论上研究了在多周期两色空间不均匀场中从预激发的He ⁺离子产生的高次谐波和单个阿秒脉冲的产生。结果表明，可以实现宽带超连续谱和单量子路径选择，然后直接获得单个15.2作为脉冲。通过在适当的时间将uv阿秒脉冲附加到两色空间不均匀场上，超连续谱的高能部分的转换效率至少提高了一个数量级，这使得能够产生强烈的单个17.3。作为脉冲。