Open AccessElectronic temperatures of terahertz quantum cascade active regions with phonon scattering assisted injection and extraction scheme
Author(s) -
Pietro Patimisco,
Gaetano Scamarcio,
Maria Vittoria Santacroce,
Vincenzo Spagnolo,
Miriam S. Vitiello,
Emmanuel Dupont,
S. R. Laframboise,
Saeed Fathololoumi,
Ghasem S. Razavipour,
Z. R. Wasilewski
Publication year - 2013
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.010172
Subject(s) - terahertz radiation , phonon , scattering , materials science , cascade , physics , quantum cascade laser , phonon scattering , ground state , condensed matter physics , laser , optics , atomic physics , optoelectronics , chemistry , chromatography
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.