Eur. Phys. J. D 26, 105-109 (2003)
https://doi.org/10.1140/epjd/e2003-00085-9

Time-frequency characterization of high-order harmonic pulses

Department of Physics, Lund Institute of Technology, P.O. Box 118, 221 00 Lund, Sweden

Corresponding author: ^a rodrigo.lopez@fysik.lth.se

Received: 20 December 2002
Published online: 24 April 2003

Abstract

We present energy-resolved cross-correlation measurements of extreme ultraviolet (XUV) pulses generated as high harmonics of femtosecond pulses from a 1 kHz titanium-sapphire laser. The harmonic pulses are probed by a fraction of the fundamental laser pulse at 800 nm, in a noncollinear geometry, allowing us to vary independently the parameters of the harmonic pump and near-infrared probe pulses. We measure the so-called “sidebands” in the photoelectron spectrum of argon corresponding to the absorption of a harmonic photon plus or minus one probe photon. Spectrally resolving the cross-correlation signal allows us to characterize the time-dependent frequency of the XUV pulse.