Effects of dc Electric Fields on Multiphoton Ionization Spectra in Cesium

M. Y. Mirza

Bernard Held, G. Mainfray, C. Manus +1 more

C. B. Collins, B. W. Johnson, Dragos Constantin Popescu +3 more

Viktor A Kovarskii

Cornelius E. Klots, R. N. Compton

Multiphoton ionization of cesium atoms shows pronounced two-photon resonances at the nd states and, to a much smaller extent, at the ns states. A dc electric field augments the ns resonances and, for a complementary reason, induces resonances at the np and nf levels. A scaling law for field-induced signals, as a function of principal quantum number, is reported. Field ionization of high Rydberg states is also conveniently studied and quantified with our technique.

Zhigang Feng, Linjie Zhang, Jianming Zhao +3 more

We investigate the field ionization spectra of ultracold cesium Rydberg atoms in dc electric field. The ionization thresholds of different electric fields are measured and shift of the ionization threshold relative to field-free ionization threshold is accurately described by (6.06 ± 0.14) F 1/2 , which is in good agreement with the classical saddle-point model for field ionization. We obtain the field-free ionization threshold of cesium (6P 3/2 ) as 19674.89 ± 2.99 cm −1 by fitting experimental data.