Valerian Thiel will defend his PhD thesis, , entitled “Modal analysis of an ultrafast frequency comb: from classical to quantum spectral correlations”, which work was accomplished in Laboratoire Kastler Brossel under the supervision of Nicolas Treps. It will take place on Monday the 19^th of October in the amphitheater Herpin, building Esclangon, at Université Pierre et Marie Curie. The defense will be in english.