Influence of electron–electron scattering on electron relaxation rates in three and four-level quantum cascade lasers in magnetic fields

The aim of this work is to calculate carrier relaxation rates from the upper laser level due to electron–electron interactions in three and four-level quantum cascade lasers (QCLs) in a strong magnetic field. The comparison between calculated results and previously obtained values for acoustical and optical-phonon scattering processes indicates that carrier–carrier scattering might have noticeable influence on laser output properties, depending on the structural design. Numerical results are presented for two λ ∼ 9 μm GaAs-based QCLs in magnetic fields between 20 T and 60 T and the band nonparabolicity is taken into account.