论文标题
时间分解OC的紫外线引发的光解离动力学
Time-resolving the UV-initiated photodissociation dynamics of OCS
论文作者
论文摘要
我们提出了一项针对$λ= 237 $ nm的紫外线兴趣后OC的光解离动力学的时间分辨研究。 OCS分子（$ x \，^1σ^+$）主要对$ 1 \，^1 \！a''$和$ 2 \，^1 \！通过耗时的强场电离观察到分解为CO和S片段，并以强烈的$ 790 $ NM激光脉冲的形式对所得CO $^+$和S $^+$片段的动能进行了成像。令人惊讶的是，在紫外线解离的S $^+$频道中观察到了$ \ sim100 $ fs的快速振荡。基于波袋动力学模拟，结合一个简单的静电相互作用模型，这些振荡与离开co $ $（x \，^1σ^+，j \ gg0）$片段的已知高度激发的旋转运动相对应，该运动的时间表为$ \ sim140 $ fs。取而代之的是，我们建议将观察到的振荡分配给$ 2 \，^3 \！a'''''''''''''或$ 2 \，^1 \！a'''''的振动波袋的激发，该振荡是分子的态度，这些分子的状态是s $（^3 \！p_ {j}）$ photopropoductss。
We present a time-resolved study of the photodissociation dynamics of OCS after UV-photoexcitation at $λ=237$ nm. OCS molecules ($X\,^1Σ^+$) were primarily excited to the $1\,^1\!A''$ and the $2\,^1\!A'$ Renner-Teller components of the $^1Σ^{-}$ and $^1\!Δ$ states. Dissociation into CO and S fragments was observed through time-delayed strong-field ionisation and imaging of the kinetic energy of the resulting CO$^+$ and S$^+$ fragments by intense $790$ nm laser pulses. Surprisingly, fast oscillations with a period of $\sim100$ fs were observed in the S$^+$ channel of the UV dissociation. Based on wavepacket-dynamics simulations coupled with a simple electrostatic-interaction model, these oscillations do not correspond to the known highly-excited rotational motion of the leaving CO$(X\,^1Σ^+,J\gg0)$ fragments, which has a timescale of $\sim140$ fs. Instead, we suggest to assign the observed oscillations to the excitation of vibrational wavepackets in the $2\,^3\!A''$ or $2\,^1\!A''$ states of the molecule that predissociate to form S$(^3\!P_{J})$ photoproducts.
