Abstract

A promising scheme for quantum networks uses single photons and atomic ensembles to interconvert between flying and stationary photonic qubits [1-3]. Thus, single-photon sources with narrow spectral bandwidth are required that efficiently couple to atomic resonances of MHz width. A purely optical approach to generate narrow-band photons uses an optical parametric oscillator (OPO) far below threshold, that is resonant for both signal and idler fields [4, 5]. The usually several 100 GHz wide phase-matching envelope then follows the Airy function of the OPO resonator and can reach MHz linewidth. Additionally, a double-resonant OPO (DRO) leads to an overall increase of the biphoton generation rate. However, neither continuous active cavity stabilization for reliable high count rates nor direct proof of antibunched single-photon emission by post-selection techniques have been incorporated in any previous realization.

© 2009 IEEE