Speaker
Description
FERMI is the seeded free electron laser (FEL) facility in operation for international users within the Elettra – Sincrotrone Trieste research center. The adoption of a seeded design provides FERMI with the desirable qualities one expects from a laser: reproducibility, stability, spectral purity, synchronization, spatial and temporal coherence [1]. The latter implies that the electric field of the FEL pulse, not just its envelope, is accessible to the experimenter and can be used as a control parameter. Many viable schemes have been developed at FERMI over the years, that can be classified as chirping the carrier frequency [2], generating twin phase-locked pulses [3], phase-locking of fundamental and second [4] or third [5] FEL harmonics, phase-locking of consecutive harmonics of the seed laser [6]. In this talk I will present the common aspects of those schemes, and their use in AMO (atomic, molecular, optical) science experiments at the Low Density Matter beamline [7]; I will explore in detail the generation of twin pulses, and their application to the excitation and manipulation of a wave-packet of He Rydberg states [8].
The results originate from the joint effort of many international laboratories and of a large
number of researchers, whose work is gratefully acknowledged.
[1] E Allaria et al., Nature Photon. 6, 699 (2013); E Allaria et al., Nature Photon. 7, 913 (2013)
[2] D Gauthier et al., Phys. Rev. Lett. 115, 114801 (2015); F Richter et al., Nature 636, 337 (2024)
[3] D Gauthier et al., Phys. Rev. Lett. 116, 024801 (2016); A Wituschek et al., Opt. Express 28, 29976 (2020); A Wituschek et al., Nature Commun. 11, 883 (2020); D Uhl et al., J. Phys. Chem. Lett. 13, 8470 (2022); D Uhl et al., J. Phys. B 55, 074002 (2022); M Fushitani et al., J. Chem. Phys. 160, 104203 (2024)
[4] K C Prince et al., Nature Photon. 10, 176 (2016); D Iablonskyi et al., Phys. Rev. Lett. 119, 073203 (2017); M Di Fraia et al., Phys. Rev. Lett. 123, 213904 (2019); D You et al., Phys. Rev. X 10, 031070 (2020)
[5] M Žitnik et al., Optica 9, 692 (2022)
[6] P K Maroju et al., Nature 578, 386 (2020); P K Maroju et al., New J. Phys. 23, 043046 (2021); P K Maroju et al., Appl. Sci. 11, 9791 (2021); P K Maroju et al., Nature Photon. 17, 200 (2023); P K Maroju et al., Commun. Phys. 8, 207 (2025)
[7] V Lyamayev et al., J. Phys. B 46, 164007 (2013); C Svetina et al., J Synchrotron Radiat. 22, 538 (2015)
[8] M Dumergue et al., Phys. Rev. Res. 6, 043323 (2024)
| Scientific Topics | AMO Physics |
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