Demonstration of a Backward-wave Parametric Down-Converter
Chun-Yao Yang1*, Jim Lin1, Chih-Sung Chuu1
1Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
* presenting author:楊竣堯,
Ultrabright source of biphotons is essential to realize a scalable quantum network, where efficient interaction of light and matter at the single photon level is necessary. Nevertheless, the widely used biphoton source today -- the forward-wave parametric down converster -- has a low brightness due to its broad gain linewidth. We demonstrate a novel biphoton source based on the backward-wave parametric down-conversion. We observe the Glauber correlation function of biphotons using the time-correlated single photon counting. We also characterize the time-energy entanglement by a Franson interferometer. Approach towards realization of an ultrabright biphoton source will also be discussed.

Keywords: Backward-wave Parametric Down-Converter, Franson interferometer