Phase-dependent loss due to nonadiabatic ionization by sub-10-fs pulses

For the first time to the author's knowledge, the effect of phase-dependent loss that can be used to stabilize the phase of a sub-10-fs laser pulse wi th respect to the envelope is shown. This loss is caused by the nonadiabati c response of an atom illuminated by a short pulse, which leads to the depe ndence of the tunneling ionization on the absolute phase of the pulse. The phase selectivity can be employed as a phase-dependent filter within the la ser cavity with important applications in nonlinear optics in the single-cy cle regime. (C) 1999 Optical Society of America OCIS codes: 320.2250, 320.7 120, 320.7160.