Pure Single Photons From Scalable Frequency Multiplexing
T. Hiemstra, T.F. Parker, P. Humphreys, J. Tiedau, M. Beck, M. Karpiński, B.J. Smith, A. Eckstein, W.S. Kolthammer, Ian A. Walmsley · Physical Review Applied · 2020
We demonstrate multiphoton interference using a resource-efficient frequency multiplexing scheme, suitable for quantum information applications that demand multiple indistinguishable and pure single photons. In our source, frequency-correlated photon pairs are generated over a wide range of frequencies by pulsed parametric down conversion. Indistinguishable single photons of a predetermined frequency are prepared using frequency-resolved detection of one photon to control an electro-optic frequency shift applied to its partner. Measured photon statistics show multiplexing increases the probability of delivering a single photon, without a corresponding increase to multiphoton events. Interference of consecutive outputs is used to bound the modal purity and demonstrate the nonclassical nature of the emitted light.