High-performance Raman memory with spatio-temporal reversal

A number of techniques exist to use an ensemble of atoms as a quantum memory for light. Many of these propose to use backward retrieval as a way to improve the storage and recall efficiency. We report on a demonstration of an off-resonant Raman memory that uses backward retrieval to achieve an efficiency of 65 +/- 6% at a storage time of one pulse duration. The memory has a characteristic decay time of 60 mu s, corresponding to a delay-bandwidth product of 160. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement