We investigate the intensity correlation properties of single photons emitted
from an optically excited single semiconductor quantum dot. The second order
temporal coherence function of the photons emitted at various wavelengths is
measured as a function of the excitation power. We show experimentally and
theoretically, for the first time, that a quantum dot is not only a source of
correlated non-classical monochromatic photons but is also a source of
correlated non-classical \emph{multicolor} photons with tunable correlation
properties. We found that the emitted photon statistics can be varied by the
excitation rate from a sub-Poissonian one, where the photons are temporally
antibunched, to super-Poissonian, where they are temporally bunched.Comment: 4 pages, 2 figure