1. Photonic Nanostructure Facility; Institute of Experimental Physics; Faculty of Physics; University of Warsaw; ul. Pasteura 5 02-093 Warsaw Poland
2. European Laboratory for Non Linear Spectroscopy (LENS); University of Florence; via Nello Carrara 1 50019 Sesto Fiorentino Italy
3. Cavendish Laboratory; Cambridge University, Cambridge; 19 JJ Thomson Avenue Cambridge CB3 0HE UK