We demonstrate efficient (>30%) quantum frequency conversion of visible single photons (711 nm) emitted by a quantum dot to a telecom wavelength (1313 nm). Analysis of the first- and second-order coherence before and after wavelength conversion clearly proves that pivotal properties, such as the coherence time and photon antibunching, are fully conserved during the frequency translation process. Our findings underline the great potential of single photon sources on demand in combination with quantum frequency conversion as a promising technique that may pave the way for a number of new applications in quantum technology.
Publication: Visible-to-Telecom Quantum Frequency Conversion of Light from a Single Quantum Emitter
Sebastian Zaske, Andreas Lenhard, Christian A. Keßler, Jan Kettler, Christian Hepp, Carsten Arend, Roland Albrecht, Wolfgang-Michael Schulz, Michael Jetter, Peter Michler, and Christoph Becher 
Phys. Rev. Lett. 109, 147404 (2012) Synopsis Pressemeldung Universität Stuttgart
Contact person: Prof. Peter Michler