Coalescence of Single Photons Emitted by Disparate Single-Photon Sources: The Example of InAs Quantum Dots and Parametric Down-Conversion Sources

Physics Department, Georgetown University, Washington, DC, USA(Dated: September 29, 2011)Single photons produced by fundamentally dissimilar physical processes will in general not beindistinguishable. We show how photons produced from a quantum dot and by parametric down-conversion in a nonlinear crystal can be manipulated to be indistinguishable. The measured two-photoncoalescence probabilityis 16%, and islimited byquantum-dot decoherence. Temporalfilteringto the quantum dot coherence time and accounting for detector time response increases this to 61%while retaining 25% of the events. This technique can connect di erent elements in a scalable quantumnetwork.