Ionization of noble gases with pulses directly from a laser oscillator.
A Ti:sapphire oscillator with an extended cavity generates pulses with 0.5 microJ energy at a repetition rate of 6 MHz and pulse durations of 50 fs. Tight focusing creates peak intensities exceeding 10(14) W/cm2, which is sufficient for ionizing helium, a nonlinear process where at least 17 photons are absorbed simultaneously.
Dewald
S
S
Max-Planck-Institut für Kernphysik, saupfercheckweg, Heidelberg, Germany. sebastian.dewald@mpi-hd.mpg.de
Lang
T
T
Schröter
C D
CD
Moshammer
R
R
Ullrich
J
J
Siegel
M
M
Morgner
U
U