We present an efficient photon-echo experiment based on atomic frequency combs [Phys. Rev. A 79, 052329 (2009)]. Echoes containing an energy of up to 35% of that of the input pulse are observed in a Pr3+-doped Y2SiO5 crystal. This material allows for the precise spectral holeburning needed to make a sharp and highly absorbing comb structure. We compare our results with a simple theoretical model with satisfactory agreement. Our results show that atomic frequency combs has the potential for high-efficiency storage of single photons as required in future long-distance communication based on quantum repeaters.
@article{arxiv.0911.2145,
title = {Towards an eficient atomic frequency comb quantum memory},
author = {A. Amari and A. Walther and M. Sabooni and M. Huang and S. Kröll and M. Afzelius and I. Usmani and B. Lauritzen and N. Sangouard and H. de Riedmatten and N. Gisin},
journal= {arXiv preprint arXiv:0911.2145},
year = {2015}
}