Heidelberg 2015 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 8: Quantum Optics II

Q 8.7: Talk

Monday, March 23, 2015, 16:00–16:15, C/HSO

Telecom-Heralded Single Photon Source for Single Atom, Single Photon Quantum Interface — •Andreas Lenhard, Matthias Bock, Stephan Kucera, José Brito, Pascal Eich, Philipp Müller, Jürgen Eschner, and Christoph Becher — FR 7.2 (Experimentalphysik), Universität des Saarlandes, 66123 Saarbrücken

In a quantum network, remote quantum systems containing stationary qubits have to be interconnected with flying qubits. For long-range connections these flying qubits should be photons at telecommunication wavelengths offering minimal loss in fiber links. However, techniques are necessary to bridge the gap between near infrared atomic transitions and telecom wavelengths.

Here we report on a source of correlated photon pairs based on spontaneous parametric downconversion (SPDC) in a singly resonant optical parametric oscillator (OPO). The signal photons are tuned to a resonance in ⁴⁰Ca⁺ at a wavelength of 854 nm while the corresponding idler photons are at 1411 nm. The spectrum of the photons is tailored by the OPO cavity to a frequency comb with a linewidth of 7 MHz for each mode. With an additional fiber Bragg grating a single mode is cut out in the telecom band. With this system we demonstrate single photon spectroscopy of the D_5/2-P_3/2 transition in a single trapped ⁴⁰Ca⁺-ion. As a basic building block for quantum networks we demonstrate the absorption of a single 854 nm photon by the ion, heralded by a telecom photon.