Optical memory bandwidth and multiplexing capacity in the erbium   telecommunication window
  We study the bandwidth and multiplexing capacity of an erbium-doped optical memory for quantum storage purposes. We concentrate on the protocol ROSE (Revival of a Silenced Echo) because it has the largest potential multiplexing capacity. Our analysis is applicable to other protocols that involve strong optical excitation. We show that the memory performance is limited by instantaneous spectral diffusion and we describe how this effect can be minimised to achieve optimal performance. 
Julian Dajczgewand, Rose Ahlefeldt, Thomas B\"ottger, Anne   Louchet-Chauvet, Jean-Louis Le Gou\"et, Thierry Chaneli\`ere
quant-ph physics.atom-ph