Optical anisotropies in strained Si/SiGe systems

Optical anisotropies were studied in two types of Si/Ge systems: strain-adjusted superlattices, and thin Ge quantum wells on Si. For the superlattices, investigations of the polarization dependence showed that the topmost valence band is of heavy-hole character. For the Ge monolayer quantum wells, the optical transitions were identified as a no-phonon transition and a TO-replica. Furthermore, the symmetry of the intermediate state over which the transitions take place at the zone-center was identified.