Update March 2019 – now in Optics Letters, DOI: 10.1364/OL.44.001427
Optically induced ultrafast switching of single photons is demonstrated by rotating the photon polarization via the Kerr effect in a commercially available single mode fiber. A switching efficiency of 97\% is achieved with a ∼1.7\,ps switching time, and signal-to-noise ratio of ∼800. Preservation of the quantum state is confirmed by measuring no significant increase in the second-order autocorrelation function g(2)(0). These values are attained with only nanojoule level pump energies that are produced by a laser oscillator with 80\,MHz repetition rate. The results highlight a simple switching device capable of both high-bandwidth operations and preservation of single-photon properties for applications in photonic quantum processing and ultrafast time-gating or switching.