title: Impact of interface roughness distributions on the operation of quantum cascade lasers.
abstract: We study the impact of interface roughness on the operation of mid-IR and THz quantum cascade lasers. Particular emphasis is given towards the differences between the Gaussian and exponential roughness distribution functions, for which we present results from simulation packages based on nonequilibrium Green's functions and density matrices. The Gaussian distribution suppresses scattering at high momentum transfer which enhances the lifetime of the upper laser level in mid-IR lasers. For THz lasers, a broader range of scattering transitions is of relevance, which is sensitive to the entire profile of the interface fluctuations. Furthermore we discuss the implementation of interface roughness within a two band model.
authors.forename: Martin
authors.initials: M
authors.lastname: Franckié
authors.forename: David O
authors.initials: DO
authors.lastname: Winge
authors.forename: Johanna
authors.initials: J
authors.lastname: Wolf
authors.forename: Valeria
authors.initials: V
authors.lastname: Liverini
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Dupont
authors.forename: Virginie
authors.initials: V
authors.lastname: Trinité
authors.forename: Jérôme
authors.initials: J
authors.lastname: Faist
authors.forename: Andreas
authors.initials: A
authors.lastname: Wacker