Approaching single-photon pulses with weak coherent states and nonlinear phase modulation

Abstract

Single-photons sources are crucial devices in the development of practical quantum communication and quantum computation. However, such sources are still a technological challenge. One option is to use weak coherent states to mimic single-photon pulses or to produce a pair of photons with parametric down conversion and to detect one of them to herald the presence of the other. In this direction, the present work shows how to produce better approximations of single-photon pulses by using a nonlinear phase modulator in a Mach-Zehnder interferometer. The proposed scheme is explained and applications are discussed.