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.
@article{arxiv.1806.01245,
title = {THz-bandwidth all-optical switching of heralded single photons},
author = {Connor Kupchak and Jennifer Erskine and Duncan G. England and Benjamin J. Sussman},
journal= {arXiv preprint arXiv:1806.01245},
year = {2019}
}