Lasing on the lithium resonance line at 670.7 nm

Stimulated emission is observed on the 2p
²
P
1/2,3/2
→ 2s
²
S
1/2
resonance transition of Li at 670.7 nm when lithium iodide (LiI) is photodissociated with the output from an ArF laser (
\lambda = 193
nm). Minimizing sodium iodide (NaI) as an impurity is crucial and the laser lifetime (several hours) appears to be limited by reaction of LiI with the walls of the quartz cell.