Spatially Resolved Spectroscopy of Single and Coupled Quantum Dots

Optical properties of single and coupled quantum dots are studied with high spatial resolution. Several techniques are used to resolve spectra of individual dots. Spatially isolated dots produced by double cleaved edge overgrowth are investigated by diffraction limited spectroscopy using a special microscope setup. Self-assembled InGaAs dots have been investigated by near-field optical techniques with metallic masks and by scanning tunneling microscopy cathodoluminescence. Photoluminescence and photoluminescence excitation spectra of selected quantum dots are discussed which reveal detailed information on ground and excited states as well as their coupling with neighboring dots.