EVALUATION OF ABSOLUTE OPTICAL OSCILLATOR-STRENGTHS FOR TRANSITIONS FROM THE A-STATE TO THE NP RYDBERG SERIES IN NO

We describe a method for calibrating oscillator strengths for transiti ons of a molecule from the A-state to the Rydberg states with the abso lute scale for the transition from the A-state to the ground state. Tw o-colour resonant four-wave mixing spectroscopy has been used to recor d the spectra for the NO transitions from the A2 Sigma(+) (upsilon' = 0) state to both the vibrationally excited X(2)Pi(3/2) (upsilon '' = 8 ) electronic ground state and to the high Rydberg series at the same t ime. By comparison with the normalised relative signal intensities, ab solute oscillator strengths for the transitions from the A-state to th r np(2)Pi(+) Rydberg series have been evaluated based on the knowledge of this parameter for the NO gamma band system. (C) 1998 Elsevier Sci ence B.V. All rights reserved.