Knowledge Bank

The $C2\Pi -X2\Sigma +(0,0)$ system of CaF around 331 nm was investigated using Doppler-free laser spectroscopy. By applying UV light from a single mode ring dye laser with intracavity fequency doubling to a molecular beam of CaF, rotational spectra could be recorded between 30190 and $30232cm-1$ at 30 MHz linewidth. Two perturbations as well as the observation of additional unassigned lines indicate the presence of another electronic state close to the C state. About 200 lines of the C-X system were assigned and rotationally analyzed. The main constants for the $C2\Pi$ state of CaF are $To=30215.962(16)cm-1,Ao=29.256(30)cm-1,Bo=0.32341(7)cm-1,po=-0.487(30)10-2cm-1$, and $qo=0.105(2)10-3cm-1$ (standard error in parentheses).