Abstract

The occurrence of direct double ionization of atoms that are exposed to intense laser fields has been known for over a decade.¹ By "direct double ionization" we mean that doubly charged ions are created directly from neutral atoms rather than through a sequential process of singly charged ions being ionized to created doubly charged ions. Recently, interest in this topic has been renewed, with the introduction of highrepetition-rate lasers, making it possible to perform statistical studies on the ionization signal and to derive various theoretical models to explain this behavior.^2-5

© 1995 Optical Society of America