Fingerprints of spatial charge transfer in Quantum Cascade Lasers

Abstract

We show that mid infrared transmission spectroscopy of a quantum cascade laser provides clear cut information on changes in charge location at different bias. Theoretical simulations of the evolution of the gain/absorption spectrum for the $\lambda \sim$ 7.4 $\mu$m InGaAs/AlInAs/InP quantum cascade laser have been compared with the experimental findings. Transfer of electrons between the ground states in the active region and the states in the injector goes in hand with a decrease of discrete intersubband absorption peaks and an increase of broad high-energy absorption towards the continuum delocalised states above the barriers.

6 pages, 5 figures

References in corpus (5)

• Nonequilibrium Green's function theory for transport and gain properties of quantum cascade structures
• On the Nature of Charge Transport in Quantum-Cascade Lasers
• Quantum-mechanical wavepacket transport in quantum cascade laser structures
• Self-Consistent Theory of the Gain Linewidth for Quantum Cascade Lasers
• Comparative analysis of resonant phonon THz quantum cascade lasers

Cited by in corpus (3)

• Monte-Carlo-based spectral gain analysis for THz quantum cascade lasers
• Monte Carlo study of carrier-light coupling in terahertz quantum cascade lasers
• Potential and limits of superlattice multipliers coupled to different input power sources