John M. J. Madey

Picosecond pump-probe using an FEL and a synchrotron source☆

Abstract We performed a two color pump-probe experiment using the Duke Storage Ring as a synchrotron light source for visible light and the Mark III FEL as a tunable, high peak power IR source. The purpose of this experiment was to measure the timing jitter between these two separately driven electron beam light sources. The visible synchrotron source was used as a probe of vibrational excitation from the IR FEL in an experiment using vibrationally-assisted fluorescence as an indicator of overlap of the IR and the visible pulses. An optical delay line in the FEL beam allowed adjustment of the arrival time of the IR pulse relative to the visible probe. The Duke Storage Ring and the Mark III IR FEL RF sources were driven by phase locked master oscillators. This two color experiment establishes an upper bound on the timing jitter between these sources of 45 ps. With these two synchronous sources, other experiments exploring coupling between electron excitation and lifetimes of vibrational excitation of fluorescence compounds in solution can be performed.