Knowledge Bank

Laser excitation spectroscopy has been used to determine rotational and vibrational constants for the $B2\Sigma$ and $X2\Sigma$ states of SrF. The advantages of using this type of spectroscopy to unravel complex spectra will be discussed. The experimental values of the constants were used to obtain an RKR potential from which Franck-Condon factors were calculated and compared to experimentally measured values. Such a comparison shows clear evidence of the heterogeneous electronic perturbation of the $B2\Sigma$ state by the nearby ($\sim$ 2000 $cm-1$) $A2\Pi$ state.