三能级体系中能量弛豫时间与荧光辐射寿命的关系

THE RELATIONSHIP BETWEEN THE ENERGY RELAXATION TIME AND FLUORESCENCE LIFETIME IN THREE LEVEL SYSTEM

随着激光技术的发展和超短脉冲激光器的出现,在研究光和物质相互作用时使我们对物质内部的能量转移以及它们之间的相互作用等快速过程的研究成为可能。测量荧光的衰减又是研究物质内部能量转移过程的常用方法。在以往的实验中我们常将荧光衰减的时间常数与上能级的寿命等同,而实际上却并非全如此。本文将从经典的速率方程出发讨论三能级体系中能量弛豫时间与激发态的荧光辐射寿命的关系。

In this paper, we discuss the relationship between the energy relaxation time and the lifetime of the fluorescence induced by a pulse laser in three level system, and show that they do not always coincide with each other.we also try to interpr et the phenomena of the fluorescence delay appeared in the ultrashort pulse expe, riment in theory, and point out the possibility obtainning the information about two relaxation processes from the measurements of the delay time of the fluorescence.