Versatile femtosecond laser sources for time–resolved studies: configurations and characterizations

The generation of tunable ultrashort laser pulses in different regions of the optical spectrum has particular significance for the study of the rapid events that arise in photochemistry and photobiology. High–resolution techniques which use such pulses to probe transient phenomena require high–repetition–rate sources which can operate over extended wavelength regions in the visible and infrared. Dramatic progress in the development of ultrafast sources has taken place during the 1990s and we present here a review of those which now represent practical tools for time–resolved studies and describe powerful characterization techniques for the pulses which they produce.