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Density-matrix theory of the optical dynamics and transport in quantum cascade structures: The role of coherence

Weber, Carsten LU ; Wacker, Andreas LU and Knorr, A. (2009) In Physical Review B (Condensed Matter and Materials Physics) 79(16).
Abstract
The impact of coherence on the nonlinear optical response and stationary transport is studied in quantum cascade laser structures. Nonequilibrium effects such as the pump-probe signals, the spatiotemporally resolved electron density evolution, and the subband population dynamics (Rabi flopping) as well as the stationary current characteristics are investigated within a microscopic density-matrix approach. Focusing on the stationary current and the recently observed gain oscillations, it is found that the inclusion of coherence leads to observable coherent effects in opposite parameter regimes regarding the relation between the level broadening and the tunnel coupling across the main injection barrier. This shows that coherence plays a... (More)
The impact of coherence on the nonlinear optical response and stationary transport is studied in quantum cascade laser structures. Nonequilibrium effects such as the pump-probe signals, the spatiotemporally resolved electron density evolution, and the subband population dynamics (Rabi flopping) as well as the stationary current characteristics are investigated within a microscopic density-matrix approach. Focusing on the stationary current and the recently observed gain oscillations, it is found that the inclusion of coherence leads to observable coherent effects in opposite parameter regimes regarding the relation between the level broadening and the tunnel coupling across the main injection barrier. This shows that coherence plays a complementary role in stationary transport and nonlinear optical dynamics in the sense that it leads to measurable effects in opposite regimes. For this reason, a fully coherent consideration of such nonequilibrium structures is necessary to describe the combined optical and transport properties. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
quantum cascade lasers, nonlinear optics, optical pumping
in
Physical Review B (Condensed Matter and Materials Physics)
volume
79
issue
16
publisher
American Physical Society
external identifiers
  • wos:000265945200077
  • scopus:66749146766
ISSN
1098-0121
DOI
10.1103/PhysRevB.79.165322
language
English
LU publication?
yes
id
ae66f4a6-ce41-4d7d-889f-08e54f160b7b (old id 1425855)
date added to LUP
2009-06-26 15:12:14
date last changed
2017-12-10 04:11:00
@article{ae66f4a6-ce41-4d7d-889f-08e54f160b7b,
  abstract     = {The impact of coherence on the nonlinear optical response and stationary transport is studied in quantum cascade laser structures. Nonequilibrium effects such as the pump-probe signals, the spatiotemporally resolved electron density evolution, and the subband population dynamics (Rabi flopping) as well as the stationary current characteristics are investigated within a microscopic density-matrix approach. Focusing on the stationary current and the recently observed gain oscillations, it is found that the inclusion of coherence leads to observable coherent effects in opposite parameter regimes regarding the relation between the level broadening and the tunnel coupling across the main injection barrier. This shows that coherence plays a complementary role in stationary transport and nonlinear optical dynamics in the sense that it leads to measurable effects in opposite regimes. For this reason, a fully coherent consideration of such nonequilibrium structures is necessary to describe the combined optical and transport properties.},
  articleno    = {165322},
  author       = {Weber, Carsten and Wacker, Andreas and Knorr, A.},
  issn         = {1098-0121},
  keyword      = {quantum cascade lasers,nonlinear optics,optical pumping},
  language     = {eng},
  number       = {16},
  publisher    = {American Physical Society},
  series       = {Physical Review B (Condensed Matter and Materials Physics)},
  title        = {Density-matrix theory of the optical dynamics and transport in quantum cascade structures: The role of coherence},
  url          = {http://dx.doi.org/10.1103/PhysRevB.79.165322},
  volume       = {79},
  year         = {2009},
}