We propose a novel method for completely characterizing ultrashort pulses at extreme-ultraviolet (XUV) wavelengths by adapting the technique of spectral phase interferometry for direct electric-field reconstruction to this spectral region. Two-electron wave packets are coherently produced by photoionizing atoms with two time-delayed replicas of the XUV pulse. For one of the XUV pulses, photoionization occurs in the presence of a strong infrared pulse that ponderomotively shifts the binding energy, thereby providing the spectral shear needed for reconstruction of the spectral phase of the XUV pulse.
© 2003 Optical Society of America
Johan Mauritsson, Rodrigo López-Martens, Anne L’Huillier, and Kenneth J. Schafer, "Ponderomotive shearing for spectral interferometry of extreme-ultraviolet pulses," Opt. Lett. 28, 2393-2395 (2003)