Multiphoton Dissociation and the Fluorescence of Nitric Oxide in Intense Laser Fields

The results are presented from experimental studies of the emission of NO radicals in a filament of femtosecond radiation produced in a N2/NO2 gas medium with total pressures of up to 1 atm. It is shown that in the recorded emission spectrum of the filament, emission transitions A2Σ+ (ν' = 0–2) – X2Π (ν'' = 0–5) of NO molecules are observed at concentrations of NO2 gas of up to 10 ppb−1. It is shown that the intensity of emission of NO A–X molecules grows along with the nitrogen pressure, due to the intermolecular nonradiative transfer of energy from the metastable $${{{\text{A}}}^{{\text{3}}}}\Sigma _{u}^{ + }$$ level of a N2 molecule to the electron A2Σ+ level of a NO molecule.