用Pump-dump-probe瞬态吸收光谱监测分子高振动激发态动力学(英)  

Pump-Dump-Probe Transient Absorption Spectroscopies in the Detection of High-Vibrational Excited Molecular Dynamics

作　　者：程继新[1] 何国钟[2] 沈振文 双丰[1] 赵仪[2] 严以京 

机构地区：[1]中国科学技术大学选键化学开放实验室,合肥230026 [2]中国科学院大连化学物理研究所分子反应动力学实验室,大连116023 [3]香港科学技术大学化学系

出　　处：《Chinese Journal of Chemical Physics》1998年第6期519-524,共6页化学物理学报（英文）

摘　　要：给出了监测外场激发下分子动力学过程的瞬态吸收信号的确切理论表述。在数值计算中，采用I2的一个二势能面系统，得到了监测基电子态高振动激发波包的吸收光谱。I2的B电子激发态被用作双光子pump－dump过程的中间态。提出了一个二阶差谱探测方案，即从弱响应区域的第5阶（pump-dump-probe）非线性光谱中提取分子动力学信息。An exact formulation is presented for calculating transient probe absorption signals to monitor the molecular dynamics excited via arbitrary external fields. The detection of a highly vibrationally pump-dumped iodine wave packet dynamics in the ground X state is numerically demonstrated by using a model I2 molecule with two Morse potential surfaces. The iodine B state serves as the intermediated to assist the optical proal. A second-order difference signal detection scheme is proposed to elucidate the molecular dynamics in the fifth-order nonlinear pump-dump-probe spectroscopic processes in the weak response regime.

关 键 词：pump-dump 瞬态吸收光谱 分子动力学 激发态 

分 类 号：O643.1[理学—物理化学]