We have studied the photoluminescence correlation from a single InAs/GaAs s
elf-assembled Stranski-Krastanow quantum dot under continuous, as well as u
nder pulsed excitation. Under weak continuous excitation, where the single
dot luminescence is due primarily to single exciton recombinations, antibun
ching is observed in the single dot emission correlation. Under weak pulsed
excitation, the number of photons emitted by the quantum dot per pulse is
close to one. We present data obtained under both conditions and are able t
o show that devices based on single quantum dots can be used to generate si
ngle photons. (C) 2001 American Institute of Physics.