Use of a dye laser for nonlinear spectroscopy of the $2^3S_1-2^3P$ transition in ${}^{6,7}Li^+$ ions

A tunable dye laser was used to measure the fine structure of the $2^3P$ multiplet and the hyperfine structure of the $2^3S_1$, and $2^3P_{1,2}$ states of ${}^{6,7}Li$ isotopes. The interaction constants for the hyperfine structure of the ${}^3S_1$ and ${}^3P$ levels were determined, showing good agreement with the theoretical data, and the splitting of the fine structure of the ${}^3P$ line was also determined. The isotope shift of this transition was found and showed good agreement with values obtained by interferometric measurements.