LASER INDUCED VIBRATION-ROTATION FLUORESCENCE AND INFRARED FORBIDDEN TRANSITIONS IN ACETYLENE

摘要

Laser induced fluorescence method has been used to study highly excited vibrational overtones in acetylene. A sample cell has been placed inside a Ti:Sapphire ring laser cavity and the total fluorescence collected by a parabolic mirror has been dispersed by a high-resolution FTIR spectrometer. The laser has pumped specific rotational slates of the CH stretching vibrational overtone state nu(1)+3 nu(3)(Sigma(u)(+)) and transitions to the symmetric state nu(1)+2 nu(3)(Sigma(g)(+)) have been observed. The observations allow determining both the vibrational term value and the rotational constant of the symmetric state, which is not accessible from the ground vibrational state by one-photon absorption. The parameters obtained sire in excellent agreement with simple local mode predictions. (C) 1997 American Institute of Physics. [References: 19]