Intersubband lifetime tuning by magnetophonon resonance in GaAs/GaAlAs quantum cascade lasers

Intersubband magneto-phonon resonance in QWs appears as a resonant relaxation of the energy of carriers in excited subbands when a quantizing high magnetic field is applied along the growth axis. The carrier lifetime shows oscillations periodic with the reciprocal of the field. We recently evidenced this effect on the light intensity of GaAs/GaAlAs quantum cascade lasers and focus here on the electron lifetime in the high magnetic field regime. The lifetime vs. magnetic field, derived from the laser threshold current, may be used to probe the electron-phonon coupling strength in this quantum dot like system