Knowledge Bank

High resolution laser spectroscopy has been employed to study metastable and excited electronic states of CaO, formed in the low pressure flame reactions $Ca+03$ and $Ca+N2O+CO$. Narrow band dye laser excitation and intermodulation spectroscopy provide for the first time rotationally resolved line patterns of the dense orange ‘acr bands’. The most prominent features in this band system have been definitively assigned to the electronic transitions $D1\Delta -a3\Pi$ and $d3\Delta -a3\Pi$. These results represent the first rotational analysis of triplet-triplet electronic transitions in an alkaline earth monoxide. The work is still under progress and new results will be discussed.