The intensity dependence of pump-induced excitonic absorption changes is studied in high-quality (Formula presented) quantum wells for different detunings and polarization configurations. For resonant excitation with increasing pump intensity a saturation of both the exciton bleaching and the induced absorption due to two-exciton resonances is observed, whereas for pumping below the exciton a characteristic polarization dependence of higher-order contributions to the optical Stark effect is found. Microscopic calculations including Coulomb correlations show that the experimental observations can be described by the coherent dynamics of single- and two-exciton resonances up to fifth order in the optical field.
|Original language||English (US)|
|Number of pages||4|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Jan 1 2000|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics