title: Electronic temperatures of terahertz quantum cascade active regions with phonon scattering assisted injection and extraction scheme.
abstract: We measured the lattice and subband electronic temperatures of terahertz quantum cascade devices based on the optical phonon-scattering assisted active region scheme. While the electronic temperature of the injector state (j = 4) significantly increases by ΔT = T(e)(4) - T(L) ~40 K, in analogy with the reported values in resonant phonon scheme (ΔT ~70-110 K), both the laser levels (j = 2,3) remain much colder with respect to the latter (by a factor of 3-5) and share the same electronic temperature of the ground level (j = 1). The electronic population ratio n(2)/n(1) shows that the optical phonon scattering efficiently depopulates the lower laser level (j = 2) up to an electronic temperature T(e) ~180 K.
authors.affiliation: Dipartimento Interateneo di Fisica, Università degli studi di Bari Aldo Moro and Politecnico di Bari, and CNR-Istituto di Fotonica e Nanotecnologie, UOS Bari, Via Amendola 173, 70126 Bari, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Patimisco
authors.forename: Gaetano
authors.initials: G
authors.lastname: Scamarcio
authors.forename: Maria Vittoria
authors.initials: MV
authors.lastname: Santacroce
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Spagnolo
authors.forename: Miriam Serena
authors.initials: MS
authors.lastname: Vitiello
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Dupont
authors.forename: Sylvain R
authors.initials: SR
authors.lastname: Laframboise
authors.forename: Saeed
authors.initials: S
authors.lastname: Fathololoumi
authors.forename: Ghasem S
authors.initials: GS
authors.lastname: Razavipour
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Wasilewski
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D012542:Scattering, Radiation; D055053:Terahertz Radiation; D013817:Thermography / Q000295:instrumentation* / Q000379:methods*