Efficient Conditional Preparation of High-Fidelity Single Photon States for Fiber-Optic Quantum Networks
Alfred B. U’Ren, Christine Silberhorn, Konrad Banaszek, Ian A. Walmsley · Physical Review Letters · 2004
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 $8.5\ifmmode\times\else\texttimes\fi{}{10}^{5}\text{ }\mathrm{c}\mathrm{o}\mathrm{i}\mathrm{n}\mathrm{c}\mathrm{i}\mathrm{d}\mathrm{e}\mathrm{n}\mathrm{c}\mathrm{e}\mathrm{s}/(\mathrm{s}\text{ }\mathrm{m}\mathrm{W})$. We exploit a novel type-II phase matching configuration in a microstructured waveguide in conjunction with an ultrashort pump.