The nonlinear intersubband absorption of a quasi-two-dimensional electron plasma in n-type modulation doped Ga0.47In0.53As/Al0.48In0.52As multiple quantum wells is investigated by femtosecond pump-probe measurements in the mid-infrared. We observe a strong dependence of the transient nonlinear intersubband absorption on the spectral position of the pulses within the intersubband absorption line. The time-resolved measurements demonstrate that the absorption dynamics is determined not only by intersubband relaxation with a time constant of 1.3 ps but also by the intrasubband thermalization and subsequent cooling of the n = 1 electron distribution.
|Original language||English (US)|
|Number of pages||3|
|Journal||Physica Status Solidi (B) Basic Research|
|State||Published - Nov 1997|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics