SO_2分子荧光辐射的时间分辨测量

Time-resolved measurement of fluorescence radiation of SO_2 molecule

用Nd·YAG激光器的四倍频输出（266nm）做激发源,得到了266 Pa样品气压条件下,SO2分子在270～470nm波长范围内的激光诱导色散荧光光谱.光谱呈现出以325.0 nm、370.0 nm和425.4 nm波长为中心的弥散结构特征,产生于受激SO2分子通过碰撞及内转换过程,布居到A1A2＋B1B1耦合激发电子态多个振转能级的荧光辐射.通过测量受激SO2分子在包络中心波长处的荧光辐射寿命随样品气压的变化,得到了受激SO2分子对应三个中心波长的自发辐射寿命及碰撞淬灭速率常数.

Laser induced dispersive fluorescence spectrum of SO2 molecule in the range of 270 - 470 ran is obtained with the quadruple harmonic output （266 nm） of a pulsed Nd·YAG laser as excitation source, The spectrum shows itself as a continuum structure centered at the wavelength of 325.0 nm, 370,0 nm and 425.4 nm. The property of the continuum structure comes from the radiation of the excited SO2 molecules distributed to many rovibronic levels of the A1A2＋B1B2 hybrid state by collision or intemal conversion process.The self -radiant lifetime and the rate constant of the collision quenching of the fluorescence corresponding to the three center wavelength of the envelope are obtained by measuring the variation of the radiant lifetime versus sample pressure.