Optically pumped ring laser oscillation in the 6Li2 molecule

Abstract
Stable unidirectional ring laser oscillation of optically pumped 6Li2 molecules was obtained for the first time. We observed transitions in the range 5237–5889 Å excited by different argon ion laser lines in the range 4579–4965 Å. Using our laser‐induced fluorescence results for this molecule, we have assigned unambiguously 23 of 27 lines to specific rovibronic transitions in the B1ΠuX1Σ+g band system of 6Li2. The optimum pressure for operation of the optically pumped 6Li2 laser was found to be ∼4 Torr.