Efficient Conditional Preparation of High-Fidelity Single Photon States for Fiber-Optic Quantum Networks

Abstract

Highly correlated photons or, accordingly, high-fidelity single-photon states are a prerequisite for closing detection loopholes in experimental tests of local realism and implementing scalable linear optical quantum computation. We demonstrate a parametric down-conversion source exhibiting a conditional detection efficiency of 51% (with corresponding preparation efficiency of 85%) and extraordinarily high detection rates of up to 8.5 x 10(5) coincidences/(s mW). We exploit a novel type-II phase matching configuration in a microstructured waveguide in conjunction with an ultrashort pump.