OPTICAL-OPTICAL DOUBLE-RESONANCE POLARIZATION SPECTROSCOPY OF THE B(1)PI STATE OF (KRB)-K-39-RB-85

High resolution spectra of the B (1) Pi<--X (1) Sigma(+) transition of the (KRb)-K-39-Rb-85 molecule have been measured with the technique o f Doppler-free optical-optical double resonance polarization spectrosc opy. Molecular constants of the B (1) Pi(v'=0-12) levels are determine d, and the RKR potential is calculated. A number of irregularities in the energies of B (1) Pi state levels and intensity anomalies are obse rved. The energy shifts of the e and f levels of the B (1) Pi state ar e studied, and the perturbations between the B (1) Pi and (3) Sigma(+) states and between the B (1) Pi and (3) Sigma(+) states are identifie d. Several transitions to the (3) Pi(1) and (3) Sigma(+) states are al so observed, and the molecular constants of the (3) Pi(1) and (3) Sigm a(+) states are evaluated. The single rovibrational level B (1) Pi(v'= 2, J'=41) is selectively excited by a single frequency laser chopped b y an electro-optical modulator, and the decay time of the resulting fl uorescence is measured at various pressures. From the Stern-Volmer plo t, the radiative lifetime and the collisional cross section of the flu orescence quenching are determined to be 11.6 ns and 29 Angstrom(2), r espectively. The intensity distribution of the dispersed fluorescence of the B (1) Pi(v'=2, J=41)-->X (1) Sigma(+)(v ''=0-11, J ''=42) trans itions is in very good agreement with the calculated values of nu(4)\[ v'=2\v '']\(2) The magnitude of the transition dipole moment is determ ined to be 9.2 D in the range of 4.08 Angstrom<R<4.73 Angstrom. These results are compared with the results of recent ab initio calculations . (C) 1996 American Institute of Physics.