摘要
利用光学双共振多光子电离光谱,测量并讨论了I_2分子的多光子跃迁通道、离子对态及转动能量弛豫。通过改变二束染料激光(ω_1:～532nm,ω_2:590～610nm)的相对延迟时间以及测量MPI信号与二束光的功率关系,把I_2的五光子电离确定为(1+2+2)过程,即:电离←离子对态←B态←X态。以B∏(O^+u)作为中间态,对I_2的离子对态进行了测量,把一组能量在53000cm^(-1)附近,间隔为37cm^(-1)的振动序列归属为离子对态中属于I^+(3P_(1,0)+I^-(~1S)组合的F(O^+u)态的高振动激发态。最后,选择F(O^+u)为探测态,测量了B∏(O^+u)态的转动能量弛豫。
Using optical-optical double resonance multiphoton ionization(OODR-MPI)spectroscopy,we have measured and analyzed the transition pathways,the ion-pair state and the rotational energy relaxation in I_2.In our measurement of the OODR spectra of I_2,using lasrs of wavelength～532nm & 590-610nm,aregular progression with a spacing of 37 cm^(-1)and total energy at 53000cm^(-1)has been recorded.By varing the delay time between the two dye lasers and by measuring the dependence between the MPI signal and the laser power,the transition pathway of the five-photons ionization is determined to be the(1+2+2)process of F-B-X and the upper resonance state is identified as the highly excited vibrational levels in the F(O^+u) state arising from the ions I^+(~3P(1,0))+I^-(~1S).Finally,the rotational energy relaxation in the B(O^+u)state is measured with the F(O^+u)as the probing state and the broadening of the spectral lines is discussed.
