The European physical journal / Web of Conferences 243, 21001 (2020). doi:10.1051/epjconf/202024321001 9th EPS-QEOD Europhoton Conference on Solid-State, Fibre, and Waveguide Coherent Light Sources, EUROPHOTON 2020, Online, Online, 2020-08-30-2020-09-04 Europhoton 2020, Prague, Czech Republic, 2020-08-30-2020-09-04 EPJ Web of Conferences, Vol 243, p 21001 (2020)