Agostini studied physics atAix-Marseille University, where he subsequently received aB.Ed. degree (licence d'enseignement) in physics in 1961, and anM.A.S. degree (diplôme d'études approfondies) in 1962. In 1968 he completed adoctoral degree there, on multilayer dielectric filters for the ultraviolet, titledAppareillage permettant la réalisation de filtres multidiélectriques UV : Étude des couches Sb2O3.[6][7][8]
After his doctorate, he became a researcher atCEA Saclay in 1969 and stayed there until 2002.[7][8] During this time, Agostini worked in the lab of Gérard Mainfray and Claude Manus, where he researched on multiphoton ionization using the powerful lasers there. They are the first to observeabove-threshold ionization in 1979 inxenon gas.[9][10][11]
In 2001, Agostini and his team at CEA Saclay along with Harm Geert Muller at the Dutch Foundation for Fundamental Research on Matter (FOM), using an advanced laser at theLaboratoire d'Optique Appliquée [fr], managed to create a train of pulses each 250attoseconds in duration. By recombining the ultrashortultraviolet pulses with the originalinfrared light they created an interference effect that allowed him to characterize the length and repetition rate of the pulses.[12][13]
Agostini received the Gustave Ribaud prize in 1995 from theFrench Academy of Sciences.[17] In 2003, he received theGay-Lussac–Humboldt Prize[18] and the Joop Los fellowship from the Dutch Foundation for Fundamental Research on Matter (FOM),[7] he also received theWilliam F. Meggers Award in Spectroscopy in 2007 from theOptical Society of America (OSA), and is aHumboldt Fellow. He was elected a Fellow of OSA in 2008 “for leadership in the development of innovative experiments providing major insights into the dynamics of the nonlinear response of atoms and molecules submitted to strong infrared laser pulses.”[7]
In 2023, he received the Nobel Prize in Physics for "experimental methods that generate attosecond pulses of light for the study of electron dynamics in matter" along withAnne L'Huillier andFerenc Krausz.[3]