Single photons for quantum information systems

This paper introduces the current state of the development of single photon sources that will play a central role in future quantum information systems. By optically pumping a system consisting of a semiconductor single quantum dot confined in a monolithic microcavity, it is possible to produce a single photon pulse stream at the Fourier transform limit with high efficiency and with a high repetition speed. It is expected that this technique will not only prove to be useful for BB84 quantum cryptography using single photons, but will also find applications in other fields such as BBM92 quantum cryptography using entangled photon pairs, quantum teleportation, quantum repeaters, and linear optical quantum computers.