PARAMETRIC 4-WAVE-MIXING IN THE H-2-SIGMA(+),H'(2)PI(UPSILON'=O) STATES OF NO

When the laser frequency was tuned through the H-2 Sigma(+), H'(2) Pi( upsilon' = 0) <-- X-2 Pi(upsilon '' = 0) two-photon transition of NO, both near-infrared and vacuum ultraviolet radiation were emitted along the laser propagation direction. The analyses of emission and excitat ion spectra revealed that the parametric four-wave mixing (PFWM) proce ss coexisted with amplified spontaneous emission. Polarization propert ies of the IR radiation are found to be dependent on the rotational le vels, Pressure and laser power behaviors of the generated waves were r eported. The mechanism of PFWM was discussed in terms of selection rul es of the relevant ro-vibronic transitions.