Conclusion

Abstract

An old field is returning into the focus of science and technology: the interaction of matter with electromagnetic radiation. Due to impressive advances in femtosecond laser technology, even small laboratories are now aquiring the ability to directly study the behavior of atoms and charged particles under a very broad range of excitation conditions. The observed phenomena include coherent effects, collective plasma oscillations, transport processes and optical response up to relativistic energies. Not only the more traditional questions of quasi–stationary behavior can be studied, but also transient processes on the scale of a few femtoseconds.