title: Comment on "counterintuitive dispersion violating Kramers-Kronig relations in gain slabs".
authors.affiliation: Moscow Institute of Physics and Technology, 9 Institutsky pereulok, Dolgoprudny, Moscow region 141701, Russia.|All-Russia Research Institute of Automatics, 22 Suschevskaya, Moscow 127055, Russia.
authors.forename: D G
authors.initials: DG
authors.lastname: Baranov
authors.affiliation: Moscow Institute of Physics and Technology, 9 Institutsky pereulok, Dolgoprudny, Moscow region 141701, Russia.|All-Russia Research Institute of Automatics, 22 Suschevskaya, Moscow 127055, Russia.
authors.forename: A A
authors.initials: AA
authors.lastname: Zyablovsky
authors.affiliation: Moscow Institute of Physics and Technology, 9 Institutsky pereulok, Dolgoprudny, Moscow region 141701, Russia.|All-Russia Research Institute of Automatics, 22 Suschevskaya, Moscow 127055, Russia.|Institute for Theoretical and Applied Electromagnetics RAS, 13 Izhorskaya, Moscow 125412, Russia.
authors.forename: A V
authors.initials: AV
authors.lastname: Dorofeenko
authors.affiliation: Moscow Institute of Physics and Technology, 9 Institutsky pereulok, Dolgoprudny, Moscow region 141701, Russia.|All-Russia Research Institute of Automatics, 22 Suschevskaya, Moscow 127055, Russia.|Institute for Theoretical and Applied Electromagnetics RAS, 13 Izhorskaya, Moscow 125412, Russia.
authors.forename: A P
authors.initials: AP
authors.lastname: Vinogradov
authors.affiliation: Department of Physics, Queens College of the City University of New York, Queens, New York 11367, USA.|The Graduate Center of the City University of New York, New York, New York 10016, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Lisyansky