We discuss experimental results on the spatial and time resolved photo
luminescence in quantum wires and dots using a micro-photoluminescence
technique. Particularly, we succeeded in measuring time resolved phot
oluminescence from a single quantum dot. Very fast diffusion dynamics
of excitons in the quantum wires were observed as well as long photolu
minescence decay times in a single quantum dot. These results demonstr
ate the one-dimensional and zero-dimensional characters of excitons in
the quantum nanostructures.