Correlated matter in radiation fields: from femtosecond spectroscopy to the free electron laser Heinrich Stolz, Ronald Redmer and Karl-Heinz Meiwes-Broer Eur. Phys. J. D, 36 2 (2005) 141 Published online: 15 November 2005 DOI: 10.1140/epjd/e2005-00270-x