Laser synchronization with a resolution down to one atomic unit of time

The ATTO group at the university of Freiburg has recently demonstrate the possibility to characterize on a single-shot basis the synchronization between the seeded free-electron laser FERMI@Elettra in Italy and an infrared pulse with a resolution down to one atomic unit of time (24 as). This is the first time that a resolution in the attosecond domain can be achieved at large scale facilities.

"Our approach will open completely new perspectives for the time-resolved investigation of attosecond dynamics at free-electron lasers" reports G. Sansone, who led the large international collaborations behind the results.

The novel technique is based on the measurement of the sidebands created by multi-infrared photon transitions in combination with a magnetic bottle electron spectrometer. The correlation plot of the single-shot sideband intensity (shown in panel a) allows one to reorder all measurements according to their relative synchronization and observe the oscillations of the sideband intensities as a function of the relative phase between the two field (panel b).

• The results are presented in the publication:
  "Attosecond coherent control of electronic wave packets in two-colour photoionization using a novel timing tool for seeded free-electron laser" P. K. Maroju et al., Nature Photonics (2023)
   
• Prof. Dr. Giuseppe Sansone (Attosecond and Strong Field Physics Group)