Fig. 5
From: Absolute strong-field ionization probabilities of ultracold rubidium atoms
87Rb energy levels and multiphoton transitions. The green arrows represent photons at 511 nm wavelength while the red arrows represent photons at 1022 nm wavelength. The excess energy of 0.67 eV transferred to the released electron is indicated as black dashed line. In a four-photon transition, the 42D and 52F states are in reach for a resonant ionization process
