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arXiv · 1201.4189

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

E. Dupont·S. Fathololoumi·Z. R. Wasilewski·G. Aers·S. R. Laframboise·M. Lindskog·A. Wacker·D. Ban·H. C. Liu
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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 $\mathrm{GaAs/Al_{0.25}Ga_{0.75}As}$ 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.

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E. Dupont, S. Fathololoumi, Z. R. Wasilewski, G. Aers, S. R. Laframboise, M. Lindskog, A. Wacker, D. Ban, H. C. Liu. 2012-01-19. A phonon scattering assisted injection and extraction based terahertz quantum cascade laser. https://doi.org/10.1063/1.3702571

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