Time-frequency characterization of femtosecond extreme ultraviolet pulses.
We present energy-resolved cross-correlation measurements of an extreme ultraviolet (XUV) pulse, generated as the fifth harmonic (15.5 eV) of an intense 80 fs laser pulse centered at 400 nm. Spectrally resolving the cross-correlation signal allows us to characterize the time-dependent frequency of the XUV pulse. We find that the fifth harmonic has a small negative chirp in excess of that predicted by perturbation theory. In addition, by manipulating the chirp of the driving laser we can induce and measure a positive or a negative chirp on the XUV pulse.
Norin
J
J
Department of Physics, Lund Institute of Technology, P.O. Box 118, S-221 00 Lund, Sweden.
Mauritsson
J
J
Johansson
A
A
Raarup
M K
MK
Buil
S
S
Persson
A
A
Dühr
O
O
Gaarde
M B
MB
Schafer
K J
KJ
Keller
U
U
Wahlström
C-G
CG
L'Huillier
A
A