Line intensities in V-type polarization labelling spectroscopy of diatomic molecules

The paper presents general rules governing the intensity factors in V-type optical double-resonance polarization labelling spectroscopy. The patterns of polarization labelling spectra are investigated for each particular combination of rotational quantum numbers in (1) Sigma-(1) Sigma and (1) Pi-(1) Sigma electronic transitions and for circularly and linearly polarized pump laser beam. The predicted intensity distributions are compared with experimental data obtained for K-2 and Na-2 molecules at B-1 Pi(u)<--X-1 Sigma(g)(+) probe, C-1 Pi(u)<--X-1 Sigma(g)(+) and A(1) Sigma(u)(+)<--X-1 Sigma(g)(+) pump transitions, respectively. The obtained results show a way to optimize the polarization labelling method by making use of the whole variety of factors affecting the intensity distribution. (C) 1997 Elsevier Science Ltd.