Comparison of THz-QCL Designs Supporting Clean N-Level Systems

Three different Terahertz quantum-cascade-laser designs supporting clean n-level systems were analyzed using nonequilibrium Green’s functions. In clean n-level systems, most of the electrons occupy the active laser levels, with thermally activated leakage channels being suppressed almost entirely up...

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Bibliographic Details
Main Authors: Nathalie Lander Gower, Silvia Piperno, Asaf Albo
Format: Article
Language:English
Published: MDPI AG 2021-06-01
Series:Photonics
Subjects:
Online Access:https://www.mdpi.com/2304-6732/8/7/248
Description
Summary:Three different Terahertz quantum-cascade-laser designs supporting clean n-level systems were analyzed using nonequilibrium Green’s functions. In clean n-level systems, most of the electrons occupy the active laser levels, with thermally activated leakage channels being suppressed almost entirely up to room temperature. Simulations of the three designs, namely a resonant phonon design, a two-well design, and a split-well direct-phonon design were investigated. The results from the simulations indicated that the two-well design would perform best overall, in terms of variations in current density, interface roughness, and ionized impurity scattering. We conclude that future research aiming to improve the temperature performance of such laser designs should be based on a two-well design.
ISSN:2304-6732