EXCITON RESONANCE REFLECTION FROM QUANTUM-WELL, QUANTUM WIRE AND QUANTUM DOT STRUCTURES

The theory of non-local dielectric response is extended to calculate reflection spectra from structures with a single quantum well (SQW), a grating of quantum well wires (QWWs) or a system of quantum dots regularly packed in a plane. There is established a functional relationship between the reflection coefficient and the envelope wave function of an exciton in the structure. We report the first observation of resonant reflection from a directly grown array of isolated QWWs. In spite of the much smaller effective volume occupied by excitons, as compared to that in a SQW, the QWW structures demonstrate shorter exciton radiative lifetimes in reasonable agreement with the theoretical estimations. © 1992.