Exciton-Polaritons in Quantum Wells and Quantum Wires

Alx Gal−xAs — GaAs multi-quantum-well systems with laterally microstructured cap layers and quantum-well-wire structures with lateral dimensions of 100–200 mn have been prepared. The photoluminescence spectra of these samples exhibit an additional emission on the high energy side of the (n=1)-electron heavy-hole free exciton transition which is strongly polarized. This emission arises from the resonantly enhanced radiative decay of quantum-well exciton polaritons, which is mediated by the microstructure. We will discuss in particular the emission efficiency and dispersion of these excitations.