pump-dump-probe technique

Transient absorption spectroscopy using three pulses (a strong pump, a dump pulse that can alter the course of the reaction photoinduced by the first pulse, and a weak probe). In general, femtosecond laser pulses are used.
Source:
PAC, 2007, 79, 293 (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 404