A phonon scattering assisted injection and extraction based terahertz quantum cascade laser

Abstract

A novel lasing scheme for terahertz quantum cascade lasers, based on consecutive phonon-photon-phonon emissions per module, is proposed and experimentally demonstrated. The charge transport of the proposed structure is modeled using a rate equation formalism. An optimization code based on a genetic algorithm was developed to find a four-well design in the $GaAs/A{\mathrm{l}}_{0.25}\mathrm{G}{\mathrm{a}}_{0.75}\mathrm{As}$ material system that maximizes the product of population inversion and oscillator strength at 150 K. The fabricated devices using Au double-metal waveguides show lasing at 3.2 THz up to 138 K. The electrical characteristics display no sign of differential resistance drop at lasing threshold, which suggests - thanks to the rate equation model - a slow depopulation rate of the lower lasing state, a hypothesis confirmed by non-equilibrium Green's function calculations.

11 pages, 10 figures

References in corpus (6)

• Phase resolved measurements of stimulated emission
• Quantum-mechanical wavepacket transport in quantum cascade laser structures
• Temperature dependence of the gain profile for THz quantum cascade lasers
• Monte-Carlo-based spectral gain analysis for THz quantum cascade lasers
• Extraction-Controlled Quantum Cascade Lasers
• Free carrier absorption in quantum cascade structures

Cited by in corpus (6)

• Thermoelectrically cooled THz quantum cascade laser operating up to 210 K
• Two-well quantum cascade laser optimization by non-equilibrium Green's function modelling
• Simulating terahertz quantum cascade lasers: Trends from samples from different labs
• Domain formation and self-sustained oscillations in quantum cascade lasers
• Numerically efficient density-matrix technique for modeling electronic transport in midinfrared quantum cascade lasers
• Partially coherent electron transport in terahertz quantum cascade lasers based on a Markovian master equation for the density matrix