Advertisement

Terahertz Quantum Cascade Lasers

  • Rüdeger Köhler
  • Alessandro Tredicucci
  • Fabio Beltram
  • Harvey E. Beere
  • Edmund H. Linfield
  • Giles A. Davies
  • David A. Ritchie
Chapter
Part of the Advances in Solid State Physics book series (ASSP, volume 43)

Abstract

Unipolar semiconductor injection lasers emitting at THz frequencies (4.3 THz, λ∼69 μm and 3.5 THz, λ∼85 μm) are discussed. The devices are based on interminiband transitions in chirped GaAs/AlGaAs superlattices that are arranged in a quantum-cascade scheme. The core featuring 100 repetitions of this type of superlattice, is embedded into a novel kind of waveguide loosely based on the surface plasmon concept, which allows to achieve low waveguide losses and high confiment factors. Continuous-wave laser emission is obtained with low tresholds of a few hundred A/cm2 up to 48 K heat sink temperature and maximum output powers of more than 4 mW. Under pulsed excitation, peak output powers of 4.5 mW at low temperatures and still 1 mW at 65 K are measured. The maximum operating temperature is 68 K. The operation of these devices is studied with the help of a Hakki-Paoli analysis.

Keywords

Lower Laser Level Laser Level Quantum Cascade Laser Peak Output Power Threshold Current Density 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Authors and Affiliations

  • Rüdeger Köhler
    • 1
  • Alessandro Tredicucci
    • 1
  • Fabio Beltram
    • 1
  • Harvey E. Beere
    • 2
  • Edmund H. Linfield
    • 2
  • Giles A. Davies
    • 2
  • David A. Ritchie
    • 2
  1. 1.NEST-INFM and Scuola Normale SuperiorePisaItaly
  2. 2.Cavendish LaboratoryUniversity of CambridgeCambridgeUnited Kingdom

Personalised recommendations