Laser induced alignment of state-selected CH3I.
Laser induced alignment of state-selected CH3I.
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DOI：
10.1039/c5cp02997j
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发表时间：
2015-09
期刊：
影响因子：
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通讯作者：
Lanhai He;J. Bulthuis;Sizuo Luo;Jia Wang;Chunjing Lu;S. Stolte;D. Ding;W. Roeterdink
中科院分区：
文献类型：
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作者：
Lanhai He;J. Bulthuis;Sizuo Luo;Jia Wang;Chunjing Lu;S. Stolte;D. Ding;W. Roeterdink
六极体态选择用于制备|jkm>=|1±1∓1>态的CH3I分子。分子在800 nm强激光场中排列，该强激光场垂直于飞行时间设置的弱静态提取场E线性极化。分子随后被第二个延时探测激光脉冲电离。结果表明，在这种几何结构中，在足够高的激光强度下，牛顿球具有足够的对称性，可以应用Abel逆变换从投射的离子图像中重建三维分布。激光诱导可控取向的上下极值分别为：取向分子<P2(cosθ)>=0.7，反取向分子<P4(cosθ)>-0.1，耦合在0.3和0.0之间。讨论了从速度图离子图像中直接提取取向参数<P2(cosθ)>和<P4(cosθ)>的方法。
Hexapole state selection is used to prepare CH3I molecules in the |JKM〉 = |1±1∓1〉 state. The molecules are aligned in a strong 800 nm laser field, which is linearly polarised perpendicular to the weak static extraction field E of the time of flight setup. The molecules are subsequently ionised by a second time delayed probe laser pulse. It will be shown that in this geometry at high enough laser intensities the Newton sphere has sufficient symmetry to apply the inverse Abel transformation to reconstruct the three dimensional distribution from the projected ion image. The laser induced controllable alignment was found to have the upper and lower extreme values of 〈P2(cos θ)〉 = 0.7 for the aligned molecule and -0.1 for the anti-aligned molecule, coupled to 〈P4(cos θ)〉 between 0.3 and 0.0. The method to extract the alignment parameters 〈P2(cos θ)〉 and 〈P4(cos θ)〉 directly from the velocity map ion images will be discussed.