Femtosecond and Attosecond Light Sources and Techniques for Spectroscopy

Abstract The quest for high‐resolution time‐resolved studies of ultrafast physical and chemical processes is an important driver behind ultrafast laser technology. The large variety of physical and chemical systems leads to the need of ultrashort laser pulses at many different wavelengths. In this article, we review the most important femtosecond and attosecond light sources available from the infrared to the X‐ray spectral region and give an introduction to the underlying physics and technology. We discuss techniques for ultrashort pulse diagnostics, which can be considered as prototypes for time‐resolved experiments in the femtosecond and attosecond domain. The topics covered in this article are intended as a starting ground and the interested reader is provided with references for further exploration.