激光脉冲对氢负离子在金属面附近光剥离的影响

利用闭合轨道理论和金属面附近氢负离子的双脉冲光剥离截面的计算公式,计算了氢负离子在金属面附近激光脉冲作用下的光剥离截面.计算结果表明:如果脉冲宽度远大于闭合轨道的回归周期时,它对光剥离截面的影响很小;当脉冲宽度小于闭合轨道的周期或者可以和闭合轨道的周期相比较时,光剥离截面的振荡幅度大大地减弱.光剥离截面除了与脉冲宽度有关外,还与双脉冲之间的时间延迟、相位差有关.对于某些相位差, 双脉冲光剥离截面的取值增大; 而对于另外一些相位差, 光剥离截面的取值减小.因此,可以利用脉冲激光来控制氢负离子在表面附近光剥离关键词：激光脉冲光剥离截面金属面闭合轨道理论

Influence of laser pulse on the photodetachment of H- ion near a metal surface

Using the closed orbit theory and the formulas of double-pulse laser pulse photodetachment cross section of H^- ion near a metal surface, we calculated the laser pulse photodetachment cross section of this system. The results suggest that for the double-pulse laser, if the pulse width is much longer than the particular closed orbit period, the contribution of that closed orbit to the photodetachment cross section is very small. If the pulse width is shorter or can be compared with the particular closed orbit period,the contribution of that closed orbit to the photodetachment cross section is reduced. The cross section depends not only on the pulse width, but also on the time delay and the relative phase of the two pulses. For certain relative phase between the two pulses, the photodetachment cross section is increased; while for other relative phases, the photodetachment cross section is reduced. Therefore, we can use the pulse laser to control the photodetachment process of H^- near a metal surface. We hope our results will be helpful for experimental research of photodetachment of negativeion influenced by pulse laser near surfaces.