We present a simple technique to reduce the emission rate of higher-order photon events from pulsed spontaneous parametric down-conversion. The technique uses extra-cavity control over a mode locked ultrafast laser to simultaneously increase repetition rate and reduce the energy of each pulse from the pump beam. We apply our scheme to a photonic quantum gate, showing improvements in the non-classical interference visibility for 2-photon and 4-photon experiments, and in the quantum-gate fidelity and entangled state production in the 2-photon case.
@article{arxiv.1110.4718,
title = {Reducing multi-photon rates in pulsed down-conversion by temporal multiplexing},
author = {Matthew A. Broome and Marcelo P. Almeida and Alessandro Fedrizzi and Andrew G. White},
journal= {arXiv preprint arXiv:1110.4718},
year = {2012}
}