title: Storage and recall of weak coherent optical pulses with an efficiency of 25%.
abstract: We demonstrate experimentally an efficient coherent rephasing scheme for the storage and recall of weak coherent light pulses in an inhomogeneously broadened optical transition in a Pr(3+):YSO crystal at 2.1 K. Precise optical pumping using a frequency stable (≈1  kHz linewidth) laser is employed to create a highly controllable atomic frequency comb structure. We report single photon level storage and retrieval efficiencies of 25%, based on coherent photon-echo-type reemission in the forward direction. The high efficiency is mainly a product of our highly controllable and precise ensemble-shaping technique. The coherence property of the quantum memory is proved through interference between a super-Gaussian pulse and the emitted echo.
authors.affiliation: Department of Physics, Lund University, P.O. Box 118, SE-22100 Lund, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Sabooni
authors.forename: F
authors.initials: F
authors.lastname: Beaudoin
authors.forename: A
authors.initials: A
authors.lastname: Walther
authors.forename: N
authors.initials: N
authors.lastname: Lin
authors.forename: A
authors.initials: A
authors.lastname: Amari
authors.forename: M
authors.initials: M
authors.lastname: Huang
authors.forename: S
authors.initials: S
authors.lastname: Kröll