Laser spectroscopy of the A∼2Π-X∼2Σ+ and B∼2Σ+-X∼2Σ+ transitions of CaCCD

In this work the A∼2Π-X∼2Σ⁺ and B∼2Σ⁺-X∼2Σ⁺ transitions in CaCCD have been studied.A rotationally-resolved spectrum of the A∼2Π-X∼2Σ⁺ transition has been obtained via laser induced fluorescence, and a low-resolution absorption spectrum of the B∼2Σ⁺-X∼2Σ⁺ transition has been detected using cavity ring down laser spectroscopy.The data permit a comparison between the molecular parameters for CaCCH and CaCCD, and isotopic relations allow us to separate the effective spin-rotation interaction from the centrifugal distortion of the spin-orbit interaction in the A∼2Π state.Consistency between the observed B∼2Σ⁺ state position and the position predicted via a unique perturber model shows that the A∼2Π and B∼2Σ⁺ states have strong 4p atomic character.