Title :
Limiting Factors to the Temperature Performance of THz Quantum Cascade Lasers Based on the Resonant-Phonon Depopulation Scheme
Author :
Chassagneux, Y. ; Wang, Q.J. ; Khanna, S.P. ; Strupiechonski, E. ; Coudevylle, J. -R ; Linfield, E.H. ; Davies, A.G. ; Capasso, F. ; Belkin, M.A. ; Colombelli, R.
Author_Institution :
Inst. d´´Electron. Fondamentale, Univ. Paris Sud, Orsay, France
Abstract :
We analyze the temperature performance of five terahertz (THz)-frequency quantum cascade lasers based on a three-quantum-well resonant-phonon depopulation design as a function of operating frequency in the 2.3-3.8-THz range. We find evidence that the device performance is limited by the interplay between two factors: 1) optical phonon scattering of thermal electrons, which dominates at shorter wavelengths, and 2) parasitic current, which dominates at longer wavelengths. We present a simple model that provides an accurate estimate of the parasitic current in these devices and predicts the dependence of the threshold current density on temperature.
Keywords :
current density; optical design techniques; quantum cascade lasers; submillimetre wave lasers; THz quantum cascade lasers; frequency 2.3 THz to 3.8 THz; optical phonon scattering; parasitic current; resonant-phonon depopulation; temperature performance; thermal electrons; three-quantum-well depopulation; threshold current density; Laser modes; Phonons; Quantum cascade lasers; Temperature; Temperature dependence; Quantum cascade lasers (QCLs); semiconductor lasers; terahertz (THz);
Journal_Title :
Terahertz Science and Technology, IEEE Transactions on
DOI :
10.1109/TTHZ.2011.2177176
