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An indirectly pumped terahertz quantum cascade laser with low injection coupling strength operating above 150 K

Razavipour, S. G.; Dupont, E.; Fathololoumi, S.; Chan, C. W. I.; Franckie, Martin LU ; Wasilewski, Z. R.; Aers, G.; Laframboise, S. R.; Wacker, Andreas LU and Hu, Q., et al. (2013) In Journal of Applied Physics 113(20).
Abstract
We designed and demonstrated a terahertz quantum cascade laser based on indirect pump injection to the upper lasing state and phonon scattering extraction from the lower lasing state. By employing a rate equation formalism and a genetic algorithm, an optimized active region design with four-well GaAs/Al0.25Ga0.75As cascade module was obtained and epitaxially grown. A figure of merit which is defined as the ratio of modal gain versus injection current was maximized at 150 K. A fabricated device with a Au metal-metal waveguide and a top n(+) GaAs contact layer lased at 2.4 THz up to 128.5 K, while another one without the top n(+) GaAs lased up to 152.5 K (1.3 (h) over bar omega/k(B)). The experimental results have been analyzed with rate... (More)
We designed and demonstrated a terahertz quantum cascade laser based on indirect pump injection to the upper lasing state and phonon scattering extraction from the lower lasing state. By employing a rate equation formalism and a genetic algorithm, an optimized active region design with four-well GaAs/Al0.25Ga0.75As cascade module was obtained and epitaxially grown. A figure of merit which is defined as the ratio of modal gain versus injection current was maximized at 150 K. A fabricated device with a Au metal-metal waveguide and a top n(+) GaAs contact layer lased at 2.4 THz up to 128.5 K, while another one without the top n(+) GaAs lased up to 152.5 K (1.3 (h) over bar omega/k(B)). The experimental results have been analyzed with rate equation and nonequilibrium Green's function models. A high population inversion is achieved at high temperature using a small oscillator strength of 0.28, while its combination with the low injection coupling strength of 0.85 meV results in a low current. The carefully engineered wavefunctions enhance the quantum efficiency of the device and therefore improve the output optical power even with an unusually low injection coupling strength. (C) 2013 AIP Publishing LLC. (Less)
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Journal of Applied Physics
volume
113
issue
20
publisher
American Institute of Physics
external identifiers
  • wos:000320132100007
  • scopus:84879108406
DOI
10.1063/1.4807580
language
English
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yes
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6d9c74ec-5ac8-46dd-838f-239c88472def (old id 3927317)
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2013-07-16 14:58:00
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2019-03-27 01:23:24
@article{6d9c74ec-5ac8-46dd-838f-239c88472def,
  abstract     = {We designed and demonstrated a terahertz quantum cascade laser based on indirect pump injection to the upper lasing state and phonon scattering extraction from the lower lasing state. By employing a rate equation formalism and a genetic algorithm, an optimized active region design with four-well GaAs/Al0.25Ga0.75As cascade module was obtained and epitaxially grown. A figure of merit which is defined as the ratio of modal gain versus injection current was maximized at 150 K. A fabricated device with a Au metal-metal waveguide and a top n(+) GaAs contact layer lased at 2.4 THz up to 128.5 K, while another one without the top n(+) GaAs lased up to 152.5 K (1.3 (h) over bar omega/k(B)). The experimental results have been analyzed with rate equation and nonequilibrium Green's function models. A high population inversion is achieved at high temperature using a small oscillator strength of 0.28, while its combination with the low injection coupling strength of 0.85 meV results in a low current. The carefully engineered wavefunctions enhance the quantum efficiency of the device and therefore improve the output optical power even with an unusually low injection coupling strength. (C) 2013 AIP Publishing LLC.},
  articleno    = {203107},
  author       = {Razavipour, S. G. and Dupont, E. and Fathololoumi, S. and Chan, C. W. I. and Franckie, Martin and Wasilewski, Z. R. and Aers, G. and Laframboise, S. R. and Wacker, Andreas and Hu, Q. and Ban, D. and Liu, H. C.},
  language     = {eng},
  number       = {20},
  publisher    = {American Institute of Physics},
  series       = {Journal of Applied Physics},
  title        = {An indirectly pumped terahertz quantum cascade laser with low injection coupling strength operating above 150 K},
  url          = {http://dx.doi.org/10.1063/1.4807580},
  volume       = {113},
  year         = {2013},
}