Method of operating a photon source

摘要

A method of operating a quantum dot photon source comprises applying an electrical bias across the source to inject carriers into at least one quantum dot to allow electrically activated emission from said at least one dot; and changing the state of carriers within the quantum dot after a predetermined time duration. Carriers are injected into the quantum dot and recombine radiatively causing a pulse of photon emission by electrical excitation. Preferably the state of the carriers in the quantum dot is changed by applying a pulsed electrical bias across the source after a length of time which is shorter than the radiative decay time. The method allows the optical output pulse duration W to be selected thus reducing jitter in the photon source.