Laser-induced fluorescence spectroscopy of the (0, 0) Schumann-Runge band of O(2).

We report laser-induced fluorescence recording and identification of the R and P branches (J = 1-21) of the (0, 0) Schumann-Runge band of molecular oxygen, excited near 202 nm by a tunable pulsed laser beam (3-MW/cm(2) maximum intensity). The intensity of the excitation spectrum varies linearly with the density of the laser power. In the conditions of the experiment, the detection limit of ground-state O(2) molecules deduced from the R(5) line is ~10(15) cm(-3).