Laser spectroscopy of core-excited levels of neutral rubidium

This Letter describes a new technique for obtaining level positions, linewidths, autoionizing times, and oscillator strengths of core-excited levels and transitions. The technique uses a tunable laser to deplete the population of a radiating core-excited level, as other levels within the core-excited manifold are accessed. Level positions and linewidths are ascertained to within 1.0 ${\mathrm{cm}}^{\mathrm{-}1}$ accuracy, and autoionizing times whose Lorentzian linewidths lie beneath the combined Doppler-hyperfine structure are measured.