Congratulations to Marie LABEYE, newly recruited as assistant professor at our department since September 2019.
Attosecond pulses are central to the investigation of valence- and core-electron dynamics on their natural timescales. The reproducible generation and characterization of attosecond waveforms has been demonstrated so far only through the process of high-order harmonic generation. Several methods for shaping attosecond waveforms have been proposed, including the use of metallic filters, multilayer mirrors and manipulation of the driving field. However, none of these approaches allows the flexible manipulation of the temporal characteristics of the attosecond waveforms, and they suffer from the low conversion efficiency of the high-order harmonic generation process. Free-electron lasers, by contrast, deliver femtosecond, extreme-ultraviolet and X-ray pulses with energies ranging from tens of microjoules to a few millijoules. Recent experiments have shown that they can generate subfemtosecond spikes, but with temporal characteristics that change shot- to-shot. Here we report reproducible generation of high-energy (microjoule level) attosecond waveforms using a seeded free-electron laser. We demonstrate amplitude and phase manipulation of the harmonic components of an attosecond pulse train in combination with an approach for its temporal reconstruction. The results presented here open the way to performing attosecond time-resolved experiments with free-electron lasers.
Attosecond pulse shaping using a seeded free-electron laser
Praveen Kumar Maroju, Cesare Grazioli, Michele Di Fraia, Matteo Moioli, Dominik Ertel1, Hamed Ahmadi, Oksana Plekan, Paola Finetti, Enrico Allaria, Luca Giannessi, Giovanni De Ninno, Carlo Spezzani, Giuseppe Penco, Simone Spampinati, Alexander Demidovich, Miltcho B. Danailov, Roberto Borghes, George Kourousias, Carlos Eduardo Sanches Dos Reis, Fulvio Billé, Alberto A. Lutman, Richard J. Squibb, Raimund Feifel, Paolo Carpeggiani, Maurizio Reduzzi, Tommaso Mazza, Michael Meyer, Samuel Bengtsson, Neven Ibrakovic, Emma Rose Simpson, Johan Mauritsson,
Tamás Csizmadia, Mathieu Dumergue, Sergei Kühn, Harshitha Nandiga Gopalakrishna, Daehyun You, Kiyoshi Ueda, Marie Labeye, Jens Egebjerg Bækhøj, Kenneth J. Schafer, Elena V. Gryzlova, Alexei N. Grum-Grzhimailo, Kevin C. Prince, Carlo Callegari & Giuseppe Sansone
Nature volume 578, pages386–391(2020)