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 = Te 4 – TL ~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 n2/n1 shows that the optical phonon scattering efficiently depopulates the lower laser level (j = 2) up to an electronic temperature Te ~180 K.
|Titolo:||Electronic temperatures of terahertz quantum cascade active regions with phonon scattering assisted injection and extraction scheme|
|Data di pubblicazione:||2013|
|Digital Object Identifier (DOI):||10.1364/OE.21.010172|
|Appare nelle tipologie:||1.1 Articolo in rivista|