Longitudinal-optical-phonon-assisted resonant excitations of US quantum dots embedded in ZnSe/(ZnSe-MgS superlattice) microcavities

摘要

CdS quantum dots (QDs) embedded in ZnSe-based microcavities were studied. The distributed Bragg reflectors (DBRs) consisted of quarter-wavelength-thick ZnSe, and ZnSe-MgS superlattices were grown, which exhibited a high reflectivity of 92% with just five periods. Microcavities with ZnSe lambda cavities were sandwiched with the DBRs and clear cavity resonance modes were observed. The US QDs were embedded at the antinode position of the ZnSe lambda cavity and were selectively excited by longitudinal-optical (LO) phonon-assisted energy relaxation to the QDs coupled to the cavity modes. This scheme made it possible to observe vacuum-field Rabi splitting with a coupling with QDs for the first time. [References: 19]