Storage and recall of weak coherent optical pulses with an efficiency of 25%.
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.
Sabooni
M
M
Department of Physics, Lund University, P.O. Box 118, SE-22100 Lund, Sweden.
Beaudoin
F
F
Walther
A
A
Lin
N
N
Amari
A
A
Huang
M
M
Kröll
S
S