Two-photon Doppler-free ultraviolet laser spectroscopy on sulphur atoms

K. -F. Lai, E. J. Salumbides, W. Ubachs

The $3p^4$ ${}^3$P${}_J$ - $3p^{3}4p$ ${}^3$P${}_J$ transition in the sulphur atom is investigated in a precision two-photon excitation scheme under Doppler-free and collision-fr…