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Pierre Agostini's experiment illuminated an argon jet with an annular $800\mathrm{nm}$ beam. A pinhole removed the annulus; a tungsten-coated mirror relayed harmonics and weak central reference into another argon jet. A magnetic-bottle electron spectrometer used time of flight and microchannel plate detectors. Glass plates varied delay. Reference-on sidebands contrasted with reference-off peaks. Atomic-phase-corrected reconstruction yielded $250$-attosecond bursts.^[ref]

The two-path attosecond phase reconstruction explains the control's purpose: adding the reference opens an interference channel. Its fitted oscillation tests phase relationships under the weak-field and atomic-response model. It does not independently reveal every target phase or an arbitrary nonperiodic optical pulse.

Pierre Agostini, Ferenc Krausz and Anne L’Huillier shared the award equally for experimental methods generating attosecond light pulses to study electron dynamics in matter.^[ref]

Pierre Agostini coauthored the measurement of a train of attosecond optical pulses synthesized from high harmonic generation. Measuring only the harmonic intensities does not determine the pulse train: the relative spectral phases are also needed. Their two-colour photoionization measurement recovered those spectral phases, giving reconstructed peaks about 250 attoseconds wide. This joined generation with a measurable test of temporal structure, rather than inferring a short pulse solely from a broad optical spectrum.^[ref]

A physicist researching high harmonic generation and interactions between lasers and matter.^[ref]