Article
Nature 414, 509-513 (29 November 2001) | doi:10.1038/35107000; Received 1 October 2001; Accepted 19 October 2001
Attosecond metrology
M. Hentschel1,2, R. Kienberger1,2, Ch. Spielmann1, G. A. Reider1, N. Milosevic1, T. Brabec1, P. Corkum3, U. Heinzmann4, M. Drescher4 and F. Krausz1
- Institut für Photonik, Technische Universität Wien, Gusshausstr. 27, A-1040 Wien, Austria
- Steacie Institute of Molecular Sciences, NRC Canada, Ottawa, Canada K1A 0R6
- Fakultät für Physik, Universität Bielefeld, D-33615 Bielefeld, Germany
- These authors contributed equally to this work
Correspondence to: F. Krausz1 Correspondence and requests for materials should be addressed to F.K. (e-mail: Email: ferenc.krausz@tuwien.ac.at).
Abstract
The generation of ultrashort pulses is a key to exploring the dynamic behaviour of matter on ever-shorter timescales. Recent developments have pushed the duration of laser pulses close to its natural limit—the wave cycle, which lasts somewhat longer than one femtosecond (1 fs = 10-15 s) in the visible spectral range. Time-resolved measurements with these pulses are able to trace dynamics of molecular structure, but fail to capture electronic processes occurring on an attosecond (1 as = 10-18 s) timescale. Here we trace electronic dynamics with a time resolution of 
150 as by using a subfemtosecond soft-X-ray pulse and a few-cycle visible light pulse. Our measurement indicates an attosecond response of the atomic system, a soft-X-ray pulse duration of 650 
150 as and an attosecond synchronism of the soft-X-ray pulse with the light field. The demonstrated experimental tools and techniques open the door to attosecond spectroscopy of bound electrons.