We show that very narrow wires and dots, exhibiting reduced dimensiona
lity features, can be obtained through etching from a single quantum w
ell structure. The importance of surface cleaning and passivation is e
mphasized. The low temperature optical data obtained on arrays of wire
s and dots allow us to estimate quantitatively the size regularity. Th
e peculiar behaviour of the photoluminescence intensity is attributed
to huge electrodynamic effects while the predicted intrinsic limitatio
ns imposed by slowed-down energy relaxation are not evidenced. We fina
lly present experimental photoluminescence and photoluminescence excit
ation spectra obtained on single wires, as small as 6 x 25 x 135 nm3.