Molecular iodine is photoexcited by a strong 800-nm laser driving several channels of multiphoton excitation. The motion following photoexcitation is probed using time-resolved x-ray scattering, which produces a scattering map $S(Q,\tau )$. Temporal Fourier-transform methods are employed to obtain a frequency-resolved x-ray-scattering signal $\tilde{S}(Q,\omega )$. Taken together, $S(Q,\tau )$ and $\tilde{S}(Q,\omega )$ separate different modes of motion so that mode-specific nuclear oscillatory positions, oscillation amplitudes, directions of motion, and times may be measured accurately. Molecular dissociations likewise have a distinct signature, which may be used to identify both velocities and dissociation time shifts and also can reveal laser-induced couplings among the molecular potentials.

中文翻译：

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使用时间分辨X射线散射表征多光子激发

分子碘是由800 nm强激光驱动多光子激发的多个通道进行光激发的。使用时间分辨的X射线散射探测光激发后的运动，这会产生散射图$\mathrm{小号}（问，\tau ）$。使用时间傅立叶变换方法来获得频率分辨的X射线散射信号$\stackrel{〜}{\mathrm{小号}}（问，\omega ）$。在一起$\mathrm{小号}（问，\tau ）$ 和 $\stackrel{〜}{\mathrm{小号}}（问，\omega ）$分离不同的运动模式，以便可以精确测量特定于模式的核振荡位置，振荡幅度，运动方向和时间。分子解离同样具有独特的特征，可以用于识别速度和解离时间偏移，还可以揭示激光诱导的分子势之间的耦合。