强红外场作用下BCl3振动态传能动力学研究

基于文献[1],本工作在较高泵浦激光能通量范围,测量并研究了BCl₃分子振动激发v_3吸收谱及时间演变,观察了v₃激发弛豫的几种能量转移过程,以及对泵浦激光能量BCl₃气压等参数的依赖关系。表明泵浦光脉冲产生一个振动态非热分布的系综,转动能量转移对引起这种非热分布有重要作用。用简化碰撞动力学模型讨论了BCl₃振动激发吸收谱的演变过程,得到振动态再分布的简单关系;Pτ_v-v≌c/K′(T_v,T₀,q)和等效振动温度、平均吸收光子数的分析表达式,与实验结果定性地符合。关键词：

THE STUDY OF VIBRATIONAL ENERGY TRANSFER DYNAMICS IN BCl3 EXCITED BY AN INTENSE INFRARED FIELD

On the basis of ref. [1], the time-resolved absorption spectrum of vibrational excited states v₃ in BCl₃ molecules are observed and investigated in higher laser energy flux. The excitation of vibrational states and a variety of energy transfer processes in relaxation, as well as their dependence on the pumping laser energy, the pressure of BCl₃ and other parameters are measured. The result shows that there exists an ensemble of nonthermal distribution in vibrational states and the rotational energy transfer plays an important role in generating this nonthermal distribution. The processes of development of the BCl₃ vi-bratioal excited absorption spectrum are discussed by using a simplified dynamical collision model. A simple relation Pr_v-v= c/K′(T_v,T<0,q) for the redistribution of the vibrational states and the analytical expressions for the equivalent vibrational temperature and the average number of the absorbed photons are obtained. They are qualitatively in agreement with experimental results.