Author Affiliations

Agata Azzolin,^1,2 Gaia Giovannetti,² Guangyu Fan,^2,3,4 Md S. Ahsan,^2,5 Sabine Rockenstein,¹ Oliviero Cannelli,² Lorenzo Colaizzi,^1,2,6 Erik P. Månsson,² Davide Faccialà,⁵ Fabio Frassetto,⁷ Dario W. Lodi,⁶ Cristian Manzoni,⁵ Rebeca Martínez Vázquez,⁵ Michele Devetta,⁵ Roberto Osellame,⁵ Luca Poletto,⁷ Salvatore Stagira,^5,6 Caterina Vozzi,⁵ Vincent Wanie,² Andrea Trabattoni,^2,8 and Francesca Calegari^1,2,3

¹Physics Department, University of Hamburg, Luruper Chausee 149, 22761 Hamburg, Germany

²Centre for Free-electron Laser Science, Deutsches Elektronen-Synchrotron, Notkestr. 85, 22607 Hamburg, Germany

³The Hamburg Centre for Ultrafast Imaging, University of Hamburg, Luruper Chausee 149, 22761 Hamburg, Germany

⁴Shangai Key Lab of Modern Optical System, University of Shangai for Science and Technology, Shangai 2000093, China

⁵Institute for Photonics and Nanotechnologies, Consiglio Nazionale delle Ricerche, piazza L. da Vinci 32, 20133 Milano, Italy

⁶Physics Department, Politecnico di Milano, piazza L. da Vinci 32, 20133 Milano, Italy

⁷Institute for Photonics and Nanotechnologies, Consiglio Nazionale delle Ricerche, via Trasea 7, 35131 Padova, Italy

⁸Institute of Quantum Optics, Leibniz Universität Hannover, Welfengarten 1, 30167 Hannover, Germany