Contents

10 August 2007
Vol 317, Issue 5839

About The Cover

Cover image expansion

COVER An array of multilayer mirrors compresses ultrabroadband laser pulses (orange beam) to 1.5 wave cycles. The attosecond x-ray pulses produced with them allow the control and real-time observation of atomic-scale electron motion. See the special section on attosecond spectroscopy beginning on page 765. Photo: Thorsten Naeser for Max Planck Institute for Quantum Optics/Laboratory for Attosecond and High-Field Physics