The Max Born Institute congratulates Anne L’Huillier, Pierre Agostini and Ferenc Krausz on receiving the 2023 Physics Nobel Prize!

Since the late 1970s, the interaction of matter with intense laser light has been intensively investigated, leading to the discovery of several unexpected, highly non-perturbative phenomena. In 1979 Pierre Agostini and co-workers reported that in an intense laser field atoms could absorb more than the minimum number of laser photons needed to drive their ionization process (Above-Threshold Ionization (ATI)). Almost a decade later, in the midst of more detailed investigations of ionization processes by strong laser fields, Anne L’Huillier discovered the process of High-Harmonic Generation (HHG), a process where the interaction of an atom with an intense laser field leads to a bundling of the energy of many incident laser photons into more energetic photons in the extreme ultra-violet or soft X-ray part of the wavelength spectrum. In subsequent years, detailed experiments and many theoretical insights (including insights by MBI-member Misha Ivanov)led to the understanding that High-Harmonic Generation can be understood in terms of a three-step picture, i.e. a sequence of (1) ionization of target atoms by the intense laser field, followed by (2) acceleration of the electron in the oscillatory laser electric field and (3) electron-ion recombination accompanied by the emission of the energetic high-harmonic photons. Once this basic picture of High-Harmonic Generation was established, the idea emerged that this might be a technique for producing attosecond laser pulses. In 2001, the “Annus mirabilis” of attosecond science, attosecond pulse production was indeed demonstrated in two pioneering experiments. First, Pierre Agostini and co-workers showed that High-Harmonic Generation using ‘standard’ femtosecond laser pulses consisting of many optical cycles produced a train of attosecond laser pulses, with two such pulses being produced during each optical cycle. Second, Ferenc Krausz and co-workers demonstrated that in the case of an extremely short driver pulse consisting of – at most – two optical cycles, the mechanism of the three-step picture could be limited to just a single occurrence, thus producing an isolated attosecond laser pulse.

Since the demonstrations of the attosecond pulse production in 2001, the attosecond science research field has flourished. At the Max Born Institute, where Agostini had been active in 2003/2004 as a recipient of a research prize by the Alexander von Humboldt Foundation, it led to the establishment of attosecond science as the leading research theme in Division A in 2010. Nowadays, with the experimental work performed in Division A (in particular, on the role of quantum entanglement on attosecond timescales) and pioneering research performed within MBI's theory department, MBI is at the forefront of research and innovation in attosecond science. At MBI and at many other places in the work, attosecond science techniques are used to resolve the role of ultrafast electron dynamics in scientific problems that span the range from atomic physics and chemical dynamics to material science and advanced electronics.  Therefore, MBI congratulates the three pioneers of attosecond science, Anne L’Huillier, Pierre Agostini and Ferenc Krausz that were awarded the 2023 Nobel Prize in Physics!

Suggestions for further reading: