Carrier Leakage Dynamics in Terahertz Quantum Cascade Lasers

Asaf Albo; Yuri V. Flores

doi:10.1109/jqe.2017.2740261

Carrier Leakage Dynamics in Terahertz Quantum Cascade Lasers

Asaf Albo, Yuri V. Flores

Massachusetts Institute of Technology

Research output: Contribution to journal › Article › peer-review

22 Scopus citations

Abstract

We analyze the output power versus temperature characteristics of two GaAs/Al_0.15Ga_0.85As terahertz quantum cascade lasers (THz-QCLs) with maximum operating temperature T_max=200 and 177 K as well as of one GaAs/Al_0.30Ga_0.70As THz-QCL with T_max=150 K and identify the thermally-activated leakage paths responsible for the laser performance degradation as the temperature increases. We identify the specific carrier leakage path active in each THz-QCL structure and are able to reconstruct the output power versus temperature profile over the entire laser operation range. We find that using high barriers in the active region design virtually eliminates carrier leakage from the upper laser level into the continuum, opening a non-radiative scattering path from the upper into the lower laser level parallel to standard electron-LO-phonon emission. This effect, together with the reduced leakage from the lower laser level into the continuum in the high-barrier device, significantly contributes to the T_max decrease from 177 to 150 K. We further show how electron leakage from the lower laser level into the continuum is enhanced in a GaAs/Al_0.15Ga_0.85As design with thin barriers, significantly improving the laser performance (T_max=200 K). Finally, we propose future design strategies for highly temperature-insensitive THz-QCLs. Our approach offers a straightforward method to analyze and troubleshoot thermally-activated carrier leakage dynamics in THz-QCLs.

Original language	English
Article number	8010809
Journal	IEEE Journal of Quantum Electronics
Volume	53
Issue number	5
DOIs	https://doi.org/10.1109/jqe.2017.2740261
State	Published - Oct 2017

Bibliographical note

Publisher Copyright:
© 1965-2012 IEEE.

Funding

Manuscript received March 29, 2017; revised June 30, 2017; accepted August 1, 2017. Date of publication August 15, 2017; date of current version August 31, 2017. The work of A. Albo was suppoerted by the Bar-Ilan University Engineering Faculty Fellowship. The work of Y. V. Flores was supported by the Research Fellowship Program of the German Research Foundation, DFG, under Grant FL945/1-1. (Corresponding author: Asaf Albo.) A. Albo is with the Faculty of Engineering, Bar-Ilan University, Ramat Gan 5290002, Israel (e-mail: [email protected]). ACKNOWLEDGMENT The authors gratefully acknowledge Prof. Qing Hu for his support in performing this research. The authors further thank John L. Reno for the MBE growths. A. Albo acknowledges the generosity and support of the Bar-Ilan University Engineering Faculty Fellowship as well as of the MIT-Technion and the Andrew and Erna Finci Viterbi Fellowships. Y. V. F. acknowledges the support of the Research Fellowship Program of the German Research Foundation, DFG (Grant FL945/1-1).

Funders	Funder number
Andrew and Erna Finci Viterbi
Bar-Ilan University Engineering
MIT-Technion
Deutsche Forschungsgemeinschaft	FL945/1-1

Keywords

Intersubband transitions
quantum cascade laser
terahertz emission

Access to Document

10.1109/jqe.2017.2740261

Cite this

@article{194d871d326a46519867c3302b74a1bd,

title = "Carrier Leakage Dynamics in Terahertz Quantum Cascade Lasers",

abstract = "We analyze the output power versus temperature characteristics of two GaAs/Al0.15Ga0.85As terahertz quantum cascade lasers (THz-QCLs) with maximum operating temperature Tmax=200 and 177 K as well as of one GaAs/Al0.30Ga0.70As THz-QCL with Tmax=150 K and identify the thermally-activated leakage paths responsible for the laser performance degradation as the temperature increases. We identify the specific carrier leakage path active in each THz-QCL structure and are able to reconstruct the output power versus temperature profile over the entire laser operation range. We find that using high barriers in the active region design virtually eliminates carrier leakage from the upper laser level into the continuum, opening a non-radiative scattering path from the upper into the lower laser level parallel to standard electron-LO-phonon emission. This effect, together with the reduced leakage from the lower laser level into the continuum in the high-barrier device, significantly contributes to the Tmax decrease from 177 to 150 K. We further show how electron leakage from the lower laser level into the continuum is enhanced in a GaAs/Al0.15Ga0.85As design with thin barriers, significantly improving the laser performance (Tmax=200 K). Finally, we propose future design strategies for highly temperature-insensitive THz-QCLs. Our approach offers a straightforward method to analyze and troubleshoot thermally-activated carrier leakage dynamics in THz-QCLs.",

keywords = "Intersubband transitions, quantum cascade laser, terahertz emission",

author = "Asaf Albo and Flores, \{Yuri V.\}",

note = "Publisher Copyright: {\textcopyright} 1965-2012 IEEE.",

year = "2017",

month = oct,

doi = "10.1109/jqe.2017.2740261",

language = "אנגלית",

volume = "53",

journal = "IEEE Journal of Quantum Electronics",

issn = "0018-9197",

publisher = "Institute of Electrical and Electronics Engineers Inc.",

number = "5",

}

TY - JOUR

T1 - Carrier Leakage Dynamics in Terahertz Quantum Cascade Lasers

AU - Albo, Asaf

AU - Flores, Yuri V.

PY - 2017/10

Y1 - 2017/10

N2 - We analyze the output power versus temperature characteristics of two GaAs/Al0.15Ga0.85As terahertz quantum cascade lasers (THz-QCLs) with maximum operating temperature Tmax=200 and 177 K as well as of one GaAs/Al0.30Ga0.70As THz-QCL with Tmax=150 K and identify the thermally-activated leakage paths responsible for the laser performance degradation as the temperature increases. We identify the specific carrier leakage path active in each THz-QCL structure and are able to reconstruct the output power versus temperature profile over the entire laser operation range. We find that using high barriers in the active region design virtually eliminates carrier leakage from the upper laser level into the continuum, opening a non-radiative scattering path from the upper into the lower laser level parallel to standard electron-LO-phonon emission. This effect, together with the reduced leakage from the lower laser level into the continuum in the high-barrier device, significantly contributes to the Tmax decrease from 177 to 150 K. We further show how electron leakage from the lower laser level into the continuum is enhanced in a GaAs/Al0.15Ga0.85As design with thin barriers, significantly improving the laser performance (Tmax=200 K). Finally, we propose future design strategies for highly temperature-insensitive THz-QCLs. Our approach offers a straightforward method to analyze and troubleshoot thermally-activated carrier leakage dynamics in THz-QCLs.

AB - We analyze the output power versus temperature characteristics of two GaAs/Al0.15Ga0.85As terahertz quantum cascade lasers (THz-QCLs) with maximum operating temperature Tmax=200 and 177 K as well as of one GaAs/Al0.30Ga0.70As THz-QCL with Tmax=150 K and identify the thermally-activated leakage paths responsible for the laser performance degradation as the temperature increases. We identify the specific carrier leakage path active in each THz-QCL structure and are able to reconstruct the output power versus temperature profile over the entire laser operation range. We find that using high barriers in the active region design virtually eliminates carrier leakage from the upper laser level into the continuum, opening a non-radiative scattering path from the upper into the lower laser level parallel to standard electron-LO-phonon emission. This effect, together with the reduced leakage from the lower laser level into the continuum in the high-barrier device, significantly contributes to the Tmax decrease from 177 to 150 K. We further show how electron leakage from the lower laser level into the continuum is enhanced in a GaAs/Al0.15Ga0.85As design with thin barriers, significantly improving the laser performance (Tmax=200 K). Finally, we propose future design strategies for highly temperature-insensitive THz-QCLs. Our approach offers a straightforward method to analyze and troubleshoot thermally-activated carrier leakage dynamics in THz-QCLs.

KW - Intersubband transitions

KW - quantum cascade laser

KW - terahertz emission

UR - https://www.scopus.com/pages/publications/85028469792

U2 - 10.1109/jqe.2017.2740261

DO - 10.1109/jqe.2017.2740261

M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???

AN - SCOPUS:85028469792

SN - 0018-9197

VL - 53

JO - IEEE Journal of Quantum Electronics

JF - IEEE Journal of Quantum Electronics

IS - 5

M1 - 8010809

ER -

Carrier Leakage Dynamics in Terahertz Quantum Cascade Lasers

Abstract

Bibliographical note

Funding

Keywords

Access to Document

Other files and links

Fingerprint

Cite this