Abstract
Intersubband electron relaxation and dephasing has been studied in InAs/AlSb multi quantum wells using time resolved femtosecond spectroscopy. The authors have measured a relaxation time T1 of 3 ps at T=300 K (and 4.6 ps at T=10 K) for a transition energy of 260 meV, which is in good agreement with our calculations. A dephasing time T2 of ~320 fs for optically excited electrons in the second subband was measured which determines the homogeneous broadening (~4.1 meV) of the absorption line.