Storage of images in atomic coherences in a rare-earth-ion-doped solid
G. Heinze,* A. Rudolf, F. Beil, and T. Halfmann†
Institut f¨ur Angewandte Physik, Technische Universit¨at Darmstadt, Hochschulstraße 6, D-64289 Darmstadt, Germany
(Received 28 August 2009; published 25 January 2010)

PHYSICAL REVIEW A 81, 011401(R) (2010)
We report on storage of images in atomic coherences driven by electromagnetically induced transparency in
a doped solid. We demonstrate image storage times up to the regime of milliseconds (i.e., more than two orders
of magnitude larger than in gaseous media). Our data also reveal an improvement in the spatial resolution of
the retrieved images by a factor of 40. The long storage times become possible by applying additional radio
frequency pulse sequences to drive rephasing of the atomic coherences.Moreover, the perturbing effect of atomic
diffusion (which significantly limits image storage times in gases) is absent in the solid. In addition, we monitored
pronounced oscillations in the intensity of the retrieved image versus the storage time. These oscillations are
due to the beating of dark-state polaritons. All of these results demonstrate the superior properties of coherently
driven optical data storage in solids.