一氧化碳的双共振多光子电离研究

用两束脉冲染料激光进行了CO的光学双共振四光子电离, 获得了转动分辩的CO A~(1Π)←X~(1Σ~+)和B~(1Σ~+)←A~(1Π)跃迁的光谱。观察到了在此2+1光子相继吸收中特有的选择定则。动力学研究表明CO基态到A~(1Π)态的双光子吸收是速率决定步骤, 其吸收截面约为1×10~(-49) cm~4 s。还测定了A~(1Π)态的单态转动传能截面。对于宇称指数e守恒、△J×±1的过程的截面约为0.05 nm; 随△J值增大而减小。对相同的△J, e正负变号的过程的截面总是小于e不变过程的截面。

AN OODR-MPI STUDY OF CARBON MONOXIDE

Optical-optical double resonance multiphoton ionization(OODR-MPI)spectroscopy is a rapidly developing, versatile technique which should find wide applications in both molecular spectroscopy and molecular dynamics. In an OODR-MPI study of CO, we irradiate the static sample cell by 2 pulsed dye laser beams. The first UV laser light (“pump beam”) resonantly pumps ground state CO to A~1∏ state via a 2-photon process. Then a second visible laser light (“probe beam”) excites CO A~1∏ to B~1∑~+. The excited B~1∑~. The excited B~1∑~+ molecule further undergoes ionization by absorbing one more UV photon, so the whole process follows a 2+1+1 photon scheme....