Parts | Days | Selection | Search | Downloads | Help

Q: Fachverband Quantenoptik und Photonik

Q 48: Quanteninformation (Quantenkommunikation)

Q 48.1: Talk

Thursday, March 13, 2008, 16:30–16:45, 1B

Two Photon Interference of Resonance Fluorescence Photons — •S. Gerber, D. Rotter, F. Dubin, and M. Mukherjee — Institut für Experimentalphysik, Universität Innsbruck, Austria

We report on two photon interference measurements of resonance fluorescence photons from trapped ions. Two indistinguishable photons impinging at two input ports of a 50/50 beam splitter coalesce, i.e. they both are leaving the device in one of the output ports. This Hong-Ou-Mandel interference is quantified by measuring correlations between the two output channels. The visibility of the two-photon interference effect determines the degree of indistinguishability of the input photons.

In a first experiment, a single trapped ion is converted into a pseudo two-photon source. The single ion resonance fluorescence is split in two parts, individually coupled into optical fibers of different length and then recombined on a beam splitter. A two-photon interference is observed with a contrast reaching 83%. The spectral brightness of our two-photon source is quantified and shown to be comparable to parametric down conversion devices [1].

In a successive experiment two-photon interference between two ions located in two separate traps is measured with up to 87% contrast. Thus, two-photon interference is used as a building block for quantum network operations.

[1] F. Dubin, D. Rotter, M. Mukherjee, S. Gerber, R. Blatt, Phys. Rev. Lett. 99, 183001 (2007)