Title :
Non-equilibrium green´s function calculation for terahertz quantum cascade lasers
Author :
Yasuda, H. ; Kubis, T. ; Vogl, P. ; Sekine, N. ; Hosako, I. ; Hirakawa, K.
Author_Institution :
Nat. Inst. of Inf. & Commun. Technol., Koganei, Japan
Abstract :
In this paper, we have calculated performance of the novel four-level THz-QCLs with the non-equilibrium Green´s function (NEGF) method. The calculation result for 40 K showed that the indirect-pump QCL has the largest THz gain. The main origin for this is that almost all electrons contribute to lasing in the new scheme. However, the advantage of gain deteriorates at 200 K due to thermally activated phonon scattering.
Keywords :
Green´s function methods; laser beams; optical pumping; phonons; quantum cascade lasers; submillimetre wave lasers; THz gain; indirect-pump QCL; nonequilibrium Green´s function calculation; temperature 200 K; temperature 40 K; terahertz quantum cascade lasers; thermally activated phonon scattering; Communication industry; Communications technology; Electron emission; Green´s function methods; Magnetic materials; Optical scattering; Phonons; Quantum cascade lasers; Resonant tunneling devices; Temperature;
Conference_Titel :
Infrared, Millimeter, and Terahertz Waves, 2009. IRMMW-THz 2009. 34th International Conference on
Conference_Location :
Busan
Print_ISBN :
978-1-4244-5416-7
Electronic_ISBN :
978-1-4244-5417-4
DOI :
10.1109/ICIMW.2009.5324924
