Free-carrier absorption in quantum cascade structures

Research output: Contribution to journalArticle


We show that the free-carrier absorption in quantum cascade lasers (QCLs) is very small and radically different from the classical Drude result due to the orthogonality between the direction of the carrier free motion and the electric field of the laser emission. A quantum mechanical calculation of the free-carrier absorption and intersubband oblique absorption induced by interface defects, Coulombic impurities, and optical phonon absorption/emission is presented for QCLs with a double-quantum-well design. The interaction between the electrons and the optical phonons dominates at room temperature.


  • F. Carosella
  • C. Ndebeka-Bandou
  • R. Ferreira
  • E. Dupont
  • K. Unterrainer
  • G. Strasser
  • Andreas Wacker
  • G. Bastard
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Condensed Matter Physics
Original languageEnglish
Article number085310
JournalPhysical Review B (Condensed Matter and Materials Physics)
Issue number8
Publication statusPublished - 2012
Publication categoryResearch

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