二个强飞秒延时激光脉冲对Na_2^+光解离的控制

TIME DELAY CONTROL OF Na + 2 PHOTODISSOCIATION BY TWO INTENSE FEMTOSECOND LASER PULSES

本文报告Ｎａ＋２离子的最低四个Σ态（１２Σｇ、１２Σｕ、２２Σｇ、２２Σｕ）在二个光脉冲作用下的解离动量谱和解离率的定量计算结果．激光波长为６８０ｎｍ，各脉冲功率１×１０１２Ｗ／ｃｍ２，脉宽５０ｆｓ，第二个脉冲的延时取０、５０、１００、…３５０ｆｓ．计算结果用三维图表出．在这些图中看到，沿相对动量坐标有单光子、双光子、三光子激发的对应的解离峰及峰值随延时的显著变化情况．各通道的解离率和总解离率列出在表中．

In this paper it is reported the quantitative calculation results of the dissociaton momentum spectra and the dissociation rates of the four lowest Σ states (1 2Σ g,1 2Σ u,2 2Σ g,2 2Σ u) of the ion Na + 2 in the two pulsed laser fields of wavelength 680nm and intensity 1×10 12 W/cm 2 at different delay times (0,50,100,…350fs).Both of the pulse widths are 50fs.The results are shown in the 3 dimensional plots.It is seen in them that there are one photon,two photon and three photon dissociation peaks in the dimension of the relative momentum and that the peak values depend dramatically on the time delay.The dissociation rates of the channals are presented in the table.The present result shows the time delay control of the branching rate of molecular dissociation by the two pulses is of high efficiency.