Importance of the microscopic effects on the linewidth enhancement factor of quantum cascade lasers

Microscopic density matrix analysis on the linewidth enhancement factor (LEF) of both mid-infrared (mid-IR) and Terahertz (THz) quantum cascade lasers (QCLs) is reported, taking into account of the many body Coulomb interactions, coherence of resonant-tunneling transport and non-parabolicity. A non-...

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Main Authors: Liu, Tao, Lee, Kenneth E., Wang, Qi Jie
Other Authors: School of Electrical and Electronic Engineering
Format: Article
Language:English
Published: 2014
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Online Access:https://hdl.handle.net/10356/96214
http://hdl.handle.net/10220/18391
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Institution: Nanyang Technological University
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spelling sg-ntu-dr.10356-962142020-09-26T22:17:58Z Importance of the microscopic effects on the linewidth enhancement factor of quantum cascade lasers Liu, Tao Lee, Kenneth E. Wang, Qi Jie School of Electrical and Electronic Engineering School of Physical and Mathematical Sciences Temasek Laboratories DRNTU::Science::Physics::Optics and light Microscopic density matrix analysis on the linewidth enhancement factor (LEF) of both mid-infrared (mid-IR) and Terahertz (THz) quantum cascade lasers (QCLs) is reported, taking into account of the many body Coulomb interactions, coherence of resonant-tunneling transport and non-parabolicity. A non-zero LEF at the gain peak is obtained due to these combined microscopic effects. The results show that, for mid-IR QCLs, the many body Coulomb interaction and non-parabolicity contribute greatly to the non-zero LEF. In contrast, for THz QCLs, the many body Coulomb interactions and the resonant-tunneling effects greatly influence the LEF resulting in a non-zero value at the gain peak. This microscopic model not only partially explains the non-zero LEF of QCLs at the gain peak, which observed in the experiments for a while but cannot be explicitly explained, but also can be employed to improve the active region designs so as to reduce the LEF by optimizing the corresponding parameters. Published version 2014-01-03T04:55:08Z 2019-12-06T19:27:19Z 2014-01-03T04:55:08Z 2019-12-06T19:27:19Z 2013 2013 Journal Article Liu, T., Lee, K. E., & Wang, Q. J. (2013). Importance of the microscopic effects on the linewidth enhancement factor of quantum cascade lasers. Optics express, 21(23), 27804-27815. 1094-4087 https://hdl.handle.net/10356/96214 http://hdl.handle.net/10220/18391 10.1364/OE.21.027804 en Optics express © 2013 Optical Society of America. This paper was published in Optics Express and is made available as an electronic reprint (preprint) with permission of Optical Society of America. The paper can be found at the following official DOI: [http://dx.doi.org/10.1364/OE.21.027804]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law. application/pdf
institution Nanyang Technological University
building NTU Library
country Singapore
collection DR-NTU
language English
topic DRNTU::Science::Physics::Optics and light
spellingShingle DRNTU::Science::Physics::Optics and light
Liu, Tao
Lee, Kenneth E.
Wang, Qi Jie
Importance of the microscopic effects on the linewidth enhancement factor of quantum cascade lasers
description Microscopic density matrix analysis on the linewidth enhancement factor (LEF) of both mid-infrared (mid-IR) and Terahertz (THz) quantum cascade lasers (QCLs) is reported, taking into account of the many body Coulomb interactions, coherence of resonant-tunneling transport and non-parabolicity. A non-zero LEF at the gain peak is obtained due to these combined microscopic effects. The results show that, for mid-IR QCLs, the many body Coulomb interaction and non-parabolicity contribute greatly to the non-zero LEF. In contrast, for THz QCLs, the many body Coulomb interactions and the resonant-tunneling effects greatly influence the LEF resulting in a non-zero value at the gain peak. This microscopic model not only partially explains the non-zero LEF of QCLs at the gain peak, which observed in the experiments for a while but cannot be explicitly explained, but also can be employed to improve the active region designs so as to reduce the LEF by optimizing the corresponding parameters.
author2 School of Electrical and Electronic Engineering
author_facet School of Electrical and Electronic Engineering
Liu, Tao
Lee, Kenneth E.
Wang, Qi Jie
format Article
author Liu, Tao
Lee, Kenneth E.
Wang, Qi Jie
author_sort Liu, Tao
title Importance of the microscopic effects on the linewidth enhancement factor of quantum cascade lasers
title_short Importance of the microscopic effects on the linewidth enhancement factor of quantum cascade lasers
title_full Importance of the microscopic effects on the linewidth enhancement factor of quantum cascade lasers
title_fullStr Importance of the microscopic effects on the linewidth enhancement factor of quantum cascade lasers
title_full_unstemmed Importance of the microscopic effects on the linewidth enhancement factor of quantum cascade lasers
title_sort importance of the microscopic effects on the linewidth enhancement factor of quantum cascade lasers
publishDate 2014
url https://hdl.handle.net/10356/96214
http://hdl.handle.net/10220/18391
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