Jiang Shicheng, Kowalewski Markus, Dorfman Konstantin E
Opt Express. 2021 Feb 15;29(4):4746-4754. doi: 10.1364/OE.414619.
It has been demonstrated that electronic coherences across many eV can be detected in pump-probe experiments involving high harmonic sources. An additional degree of control over the phase matching can be employed by investigating a more general class of multi-wave mixing. Non-collinear multi-wave mixing of high harmonics with energy (qω + qω) can be selectively detected along the direction of (qk + qk). Simulations based on a recently developed semi-perturbative approach show that only the specific harmonic signals with qω close to the energy difference between ground state and excited states are observable when the two input pulses are well separated in time. The coherent dynamics between different states can be selectively tracked by detecting the time-delay dependent signals with different qk, which can overcome the potential spectral congestion in real experiments. Additionally, such non-collinear geometry can be used to separate the dephasing induced decay and collision induced recovery behaviors of pump-probe high harmonic signal typically observed in the time-resolved high harmonic pump-probe signals.
已经证明，在涉及高谐波源的泵浦-探测实验中，可以检测到跨越许多电子伏特的电子相干性。通过研究更一般的多波混频类别，可以对相位匹配进行额外程度的控制。高谐波与能量（qω + qω）的非共线多波混频可以沿（qk + qk）方向被选择性地检测到。基于最近开发的半微扰方法的模拟表明，当两个输入脉冲在时间上充分分离时，只有qω接近基态和激发态之间能量差的特定谐波信号是可观测的。通过检测具有不同qk的时间延迟相关信号，可以选择性地跟踪不同状态之间的相干动力学，这可以克服实际实验中潜在的光谱拥塞。此外，这种非共线几何结构可用于分离在时间分辨高谐波泵浦-探测信号中通常观察到的泵浦-探测高谐波信号的退相诱导衰减和碰撞诱导恢复行为。
