强激光场中氢负离子双光子电离能量谱的研究

摘要

We studied the energy spectrum of H ion double-photon ionization in an intense laser field u-sing strong field approximation(SFA) method. Our results show that angular distributions of the energy spectrum for H~ ion during the ionization process is good agreement with experimental data. Further investigation shows that the energy spectrum of H" ion double-photon ionization during the ionization process in a laser field is relative to the ponderomotive potential of electron. The ponderomotive potential of photoelectron is large when the laser intensity is high, thus the position of energy spectrum peak for the high laser intensity is shifted to low energy clearly. Our results show that SFA is a good method for investigate ionization of negative ions in an intense laser field.%利用强场近似(Strong field approximation,SFA)方法研究氢负离子(H-)在强激光场中双光子电离的能量谱,所得到的电离谱随角度的变化规律与实验结果符合得很好.进一步的研究表明,H-离子在强激光场中双光子电离的能量谱与有质动力能有关.激光场强度越大,光电子的有质动力能也越大,能量谱向左移动越明显.我们的结果表明,使用强场近似是一种研究负离子在强激光场中电离过程的有效方法.