Probing scattering mechanisms with symmetric quantum cascade lasers.

  title={Probing scattering mechanisms with symmetric quantum cascade lasers.},
  author={Christoph Deutsch and Hermann Detz and Tobias Zederbauer and Aaron Maxwell Andrews and Pavel Klang and Tillmann Kubis and Gerhard Klimeck and Manfred Erwin Schuster and Werner Schrenk and Gottfried Strasser and Karl Unterrainer},
  journal={Optics express},
  volume={21 6},
A characteristic feature of quantum cascade lasers is their unipolar carrier transport. We exploit this feature and realize nominally symmetric active regions for terahertz quantum cascade lasers, which should yield equal performance with either bias polarity. However, symmetric devices exhibit a strongly bias polarity dependent performance due to growth direction asymmetries, making them an ideal tool to study the related scattering mechanisms. In the case of an InGaAs/GaAsSb heterostructure… CONTINUE READING