Measurement of /spl sim/10 fs XUV pulses from high-order harmonic generation

Summary form only given. High harmonic generation is unique as a source of coherent soft-X-ray (XUV) light because of its extremely short pulse duration, high spatial coherence, and compact size. Several theories have predicted that attosecond pulses might be generated using high order harmonic generation excited by ultrashort pulses. However, to date the fastest harmonic pulse duration measurements published were performed using laser pulses longer than 25 fs. In this work, we experimentally demonstrate a cross-correlation measurement which sets an upper limit of /spl sim/10 fs on the pulse duration of XUV harmonics.