Ac stark shifts induced by a YAG laser in the nP and nF Rydberg series in xenon

Summary, in English

Nonresonant ac Stark shifts of Rydberg states in Xe have been investigated by probing an atomic transition with a weak UV light in the presence of an intense YAG-laser pulse. Rydberg atoms produced through two-photon excitation, 5p → np (n = 15-48) and 5p → nf (n = 12-49), are subsequently ionized. IR-laser-induced shifts of the resonant ionization profiles are then measured. The measured shift, 3.9 ± 0.3 cm^-1 at 10¹⁰ W cm^-2, is more than a factor of 2 smaller than that expected from the basis of ponderomotive term, 8.5 cm^-1 at 1010 W cm^-2. In addition, the shift varies linearly as a function of the IR-laser intensity and does not depend on the principal quantum number of the np and nf series investigated here.