Inter-Landau level scattering and LO-phonon emission in Terahertz quantum cascade laser

Nicolas Péré-Laperne (1) , Louis-Anne de Vaulchier (1) , Yves Guldner (1) , Gérald Bastard (1) , Giacomo Scalari (2) , Marcella Giovannini (2) , Jérôme Faist (2) , Angela Vasanelli (3) , Sukhdeep Dhillon (3) , Carlo Sirtori (3)

1 LPA - Laboratoire Pierre Aigrain
2 Institute of Physics
3 MPQ (UMR_7162) - Laboratoire Matériaux et Phénomènes Quantiques

A Terahertz Quantum Cascade Laser (THz QCL) structure based on a bound to continuum and LO-phonon extraction stage is studied under a strong magnetic field. Two series of power oscillations as a function of magnetic field are observed. Comprehensive simulations of the lifetimes allow the first series to be assigned to interface roughness (elastic) and the second to LO phonon scattering (inelastic) of hot carriers in an excited Landau level, previously unobserved in terahertz QCL. We demonstrate that for the latter, the thermal electron distribution in the upper laser state leads to a breaking of the population inversion and hence laser action.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Nicolas Péré-Laperne, Louis-Anne de Vaulchier, Yves Guldner, Gérald Bastard, Giacomo Scalari, et al.. Inter-Landau level scattering and LO-phonon emission in Terahertz quantum cascade laser. Applied Physics Letters, 2007, 91, pp.062102. ⟨hal-00156810⟩