Abstract

Bright sources of on-demand single photons are a fundamental resource [1], required for linear optical quantum computing and quantum communication. Heralded single photon sources are based on photon-pair generation in nonlinear optical media, such as χ⁽²⁾ crystals and χ⁽³⁾ waveguides [2,3], where one photon in the pair is detected to herald the existance of the remaining photon. The number of photon pairs generated is governed by Poisson statistics, thus sources must operate in a regime where the probability of generating more than one pair is low, and so the probability of generating one pair is typically below 0.1. Attenuated laser sources also face the problem of generating multiple photons, without the advantage of heralding. On-demand sources based on atom-like systems offer the certainty of a single photon, but have additional challenges yet to be overcome. However, by using either spatial [4-6] or temporal multiplexing [7], the relationship between single and multi-photon generation can be decoupled allowing photon-pair sources to approximate a true on-demand single photon source. Previous reports have used alignment sensitive bulk-optics that are challenging to scale-up.

© 2013 IEEE