In this paper, we describe how to realize conditional frequency entanglement swapping and to produce probabilisticly a three-photon frequency entangled state from two pairs of frequency entangled states by using an Acoustic-Optical-Modulator. Both schemes are very simple and may be implementable in practice.
@article{arxiv.quant-ph/0005065,
title = {Manipulating the frequency entangled states by acoustic-optical-modulator},
author = {Bao-Sen Shi and Yun-Kun Jiang and Guang-Can Guo},
journal= {arXiv preprint arXiv:quant-ph/0005065},
year = {2016}
}