We demonstrate storage of polarization-entangled photons for 125 µs, a record storage time to date, in a 25-km-long fiber spool, using a telecommunications-band fiber-based source of entanglement. With this source we also demonstrate distribution of polarization entanglement over 50 km by separating the two photons of an entangled pair and transmitting them individually over separate 25-km fibers. The measured two-photon fringe visibilities were 82% in the storage experiment and 86% in the distribution experiment. Preservation of polarization entanglement over such long-distance transmission demonstrates the viability of all-fiber sources for use in quantum memories and quantum logic gates.
© 2005 Optical Society of America
Xiaoying Li, Paul L. Voss, Jun Chen, Jay E. Sharping, and Prem Kumar, "Storage and long-distance distribution of telecommunications-band polarization entanglement generated in an optical fiber," Opt. Lett. 30, 1201-1203 (2005)