我们用脉冲光学 光学双共振荧光激发谱 (OODR) ,测量了在 35 5 0 0～ 380 0 0cm- 1 能量范围内的里德堡态 ,观察到7Li2 31 Πg 态的 10个振动能级。本文对观测的 31 Пg 态的 14 6条激发谱线进行了归属 ,得到了新的Dunham常数 ,RKR势能曲线以及A1 Σ+ u 到 31 Πg 态跃迁的夫兰克 康登因子 ,并且讨论了 31 Πg 态的双重分裂以及与附近里德堡态F(4) 1 Σ+g ,5 1 Σ+g ,6 1 Σ+g 和G(2 ) 1 Πg 的微扰。发现在我们的实验精度下(0 2cm- 1 ) 31 Πg 态的双重分裂可以忽略 Using pulsed optical double resonance fluorescence excitation spectroscopy (OODR), we measured the Rydberg states in the energy range of 35 5 0 0 ~ 380 0 0 cm -1 and observed 10 vibrational levels in the 7Li 2 31 Πg state. In this paper, 14 6 excitation spectra in 31 Пg states are assigned, and new Dunham constant, RKR potential energy curve and the Frank positive factor of transition from A1Σ + u to 31Πg state are discussed, and 31 Πg states, and perturbations with nearby Rydberg states F (4) 1 Σ + g, 5 1 Σ + g, 6 1 Σ + g and G (2) 1Πg. It was found that under the experimental accuracy of our experiment (0 2cm -1), the double division of 31 Πg state was negligible