Figure 2

Cloud-averaged transition probability without considering spontaneous emission for a monochromatic pulse (blue) and three polychromatic spectra A, B (equal amplitude, \(N=10\)) and C (\(\alpha =0.7\)) with the same total Rabi frequency \(\Omega _{T}=4.8\text{MHz}\) (which correponds for instance to a power \(P=100~\text{mW}\) on the \(^{1}S_{0}{-}^{3} P_{1}\) transition in ⁸⁷Sr). Combs B and C have no resonant component and the aspect ratio is \(\epsilon =1\) in all three cases. Here, \(\sigma _{\text{pos}}=2~\text{mm}\) and \(\sigma _{\text{beam}} = 5~\text{mm}\). While polychromatic fields display an enhanced efficiency even at high temperatures (left), contrast loss over time can be eliminated by removing the resonant component (middle), and smooth population transfers can be performed by shaping the pulse power spectrum (right)