NO分子420～495nm波长范围的共振多光子离化谱

Resonance Multi-photon Ionization Spectrum of NO in 420～495 nm Wavelength Region

以皮秒Nd:YAG激光器泵浦光学参量发生/放大器(OPG/OPA)做激发源,得到了NO分子在420～495nm波长内的共振增强多光子离化(REMPI)谱,离化信号随激光强度的近4次方变化关系表明,NO分子通过吸收4个光子而离化,NO分子由基电子态X2∏(v"=0)经过中间共振态A2∑(v′=0.1)、F2Δ(v′=0,1,2)和H2∑(v′=0,1,2),通过(2+2)或(3+1)过程而离化。利用最小二乘法拟合获得了NO分子A2∑、F2Δ和H2∑态的振动常数及平衡位置的力常数,结果与文献报道基本符合。

Resonance-enhanced multi-photon ionization(REMPI) spectrum of NO in the wavelength region of 420～495 nm was gained using optical parameter generator and amplifier(OPG/OPA) as exciting source.The OPG/OPA is pumped by a Nd:YAG laser.The near quartic relationship of the ionization signal versus laser intensity indicates that NO molecule is ionized through a four-photon process.The ionization pathway can be shown as that NO molecule is ionized by a (2+2) or (3+1) REMPI process.The intermediate resonant states are A^2∑(v′=0.1),F^2Δ(v′=0,1,2,3) and H^2∑(v′=0,1,2).The molecule constants about NO (A^2∑,F^2Δ,H^2∑) states were calculated using the method of least-square fitting.The results are in agreement with relative reference reports.