Abstract

In this paper we discuss the stabilization of two-electron atoms in ultrastrong, ultrashort laser pulses. We try to judge stabilization from the study of energy spectra of the bound states surviving after the pulse. These survivors include the ground and highly excited states of helium atoms and the ground and Rydberg states of He⁺ ions. We interpret the absence of the low-lying excited states of He⁺ as evidence of one-electron stabilization. Qualitative arguments are given to justify this conclusion. The distinction is made, however, between stabilization, as a one- electron phenomenon of prolonged lifetime in the ultrastrong laser field and real diminishing of total probability of ionization with growing intensity. The latter can be affected in multielectron systems by electron-electron collisions and autoionization, while both processes are modified by the strong field.

© 1993 Optical Society of America