Belmiro Chu Chon-Teng, Sheu Yae-Lin, Chu Shih-I
Opt Express. 2021 Oct 11;29(21):32900-32909. doi: 10.1364/OE.438212.
We present ab initio simulations of optimal control of high-order-harmonic generation spectra that enable the synthesis of a circularly polarized 53-attosecond pulse in a single Helium atom response. The Bayesian optimization is used to achieve control of a two-color polarization gating laser waveform such that a series of harmonics in the plateau region are phase-matched, which can be used for attosecond pulse synthesis. To find the underlying mechanisms for generating these harmonics, we perform a wavelet analysis for the induced dipole moment in acceleration form, and compare the time-energy representation with the quantum paths extracted from the semiclassical calculation. We found that these coherent harmonics are excited along the short trajectories. The proposed method has the potential to migrate to laboratories for generation of isolated circularly polarized ultrashort attosecond pulses.
我们展示了对高次谐波产生光谱的最优控制的从头算模拟，该模拟能够在单个氦原子响应中合成圆偏振的53阿秒脉冲。贝叶斯优化用于实现对双色偏振门控激光波形的控制，使得平台区域中的一系列谐波能够相位匹配，这可用于阿秒脉冲合成。为了找到产生这些谐波的潜在机制，我们对加速度形式的感应偶极矩进行了小波分析，并将时间 - 能量表示与从半经典计算中提取的量子路径进行比较。我们发现这些相干谐波是沿着短轨迹激发的。所提出的方法有潜力迁移到实验室用于产生孤立的圆偏振超短阿秒脉冲。
