Spectroscopic measurements of sub-laser linewidth autoionization rates

The authors have simply determined autoionizing rates for states that have autoionization-induced linewidths smaller than the linewidth of their laser. By increasing our laser power to depletion-broaden the transition they have increased the apparent width of the transition beyond the laser's linewidth. The natural autoionization width can then be inferred from the laser power required to depletion-broaden the transition