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Ignition of quantum cascade lasers in a state of oscillating electric field domains

Winge, David O. LU ; Dupont, Emmanuel and Wacker, Andreas LU (2018) In Physical Review A 98(2).
Abstract

Quantum cascade lasers (QCLs) are generally designed to avoid negative differential conductivity (NDC) in the vicinity of the operation point in order to prevent instabilities. We demonstrate that the threshold condition is possible under an inhomogeneous distribution of the electric field (domains) and leads to lasing at an operation point with a voltage bias normally attributed to the NDC region. For our example, a terahertz QCL operating up to the current maximum temperature of 199 K, the theoretical findings agree well with the experimental observations. In particular, we experimentally observe self-sustained oscillations with GHz frequency before and after threshold. These are attributed to traveling domains by our simulations.... (More)

Quantum cascade lasers (QCLs) are generally designed to avoid negative differential conductivity (NDC) in the vicinity of the operation point in order to prevent instabilities. We demonstrate that the threshold condition is possible under an inhomogeneous distribution of the electric field (domains) and leads to lasing at an operation point with a voltage bias normally attributed to the NDC region. For our example, a terahertz QCL operating up to the current maximum temperature of 199 K, the theoretical findings agree well with the experimental observations. In particular, we experimentally observe self-sustained oscillations with GHz frequency before and after threshold. These are attributed to traveling domains by our simulations. Overcoming the design paradigm to avoid NDC may allow for the further optimization of QCLs with less dissipation from stabilizing background currents.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review A
volume
98
issue
2
publisher
American Physical Society
external identifiers
  • scopus:85052118455
ISSN
2469-9926
DOI
10.1103/PhysRevA.98.023834
language
English
LU publication?
yes
id
3eec8a8a-2126-4d22-85ff-2d1c01146b51
date added to LUP
2018-09-26 14:46:28
date last changed
2019-05-21 04:11:33
@article{3eec8a8a-2126-4d22-85ff-2d1c01146b51,
  abstract     = {<p>Quantum cascade lasers (QCLs) are generally designed to avoid negative differential conductivity (NDC) in the vicinity of the operation point in order to prevent instabilities. We demonstrate that the threshold condition is possible under an inhomogeneous distribution of the electric field (domains) and leads to lasing at an operation point with a voltage bias normally attributed to the NDC region. For our example, a terahertz QCL operating up to the current maximum temperature of 199 K, the theoretical findings agree well with the experimental observations. In particular, we experimentally observe self-sustained oscillations with GHz frequency before and after threshold. These are attributed to traveling domains by our simulations. Overcoming the design paradigm to avoid NDC may allow for the further optimization of QCLs with less dissipation from stabilizing background currents.</p>},
  articleno    = {023834},
  author       = {Winge, David O. and Dupont, Emmanuel and Wacker, Andreas},
  issn         = {2469-9926},
  language     = {eng},
  month        = {08},
  number       = {2},
  publisher    = {American Physical Society},
  series       = {Physical Review A},
  title        = {Ignition of quantum cascade lasers in a state of oscillating electric field domains},
  url          = {http://dx.doi.org/10.1103/PhysRevA.98.023834},
  volume       = {98},
  year         = {2018},
}