Wells E, Ben-Itzhak I, Jones R R
Department of Physics, University of Virginia, Charlottesville, Virginia 22904-4714, USA.
Phys Rev Lett. 2004 Jul 9;93(2):023001. doi: 10.1103/PhysRevLett.93.023001. Epub 2004 Jul 6.
Ionization of atoms by the spatial gradient of the pondermotive potential in a focused laser beam is investigated. Rydberg ions, formed during the interaction of noble gas atoms with an intense laser pulse, are used to probe the gradient field. Rydberg ion species with higher ionization potentials are produced at locations where the gradient field is largest. The measured Rydberg ion yields differ dramatically from estimates that ignore gradient-field ionization, but are in good agreement with predictions that include the effect.
研究了聚焦激光束中 ponderomotive 势的空间梯度对原子的电离作用。利用稀有气体原子与强激光脉冲相互作用过程中形成的里德堡离子来探测梯度场。在梯度场最大的位置产生了具有较高电离势的里德堡离子种类。测得的里德堡离子产率与忽略梯度场电离的估计值有很大差异，但与包含该效应的预测结果吻合良好。
