Refractive index control for optical quantum storage

Abstract

Manipulating refractive index in time allows one to implement quantum storage in an extended resonant atomic system without recourse to inhomogeneous broadening of optical transitions or amplitude modulation of control fields, which when combined with other storage techniques provides the possibility to improve mode or channel capacity of optical storage devices. We discuss different methods of refractive index manipulation in the context of quantum storage applications, giving special attention to a simple frequency shift of an absorption structure relative to the resonant energy levels. We show that a linear modulation of refractive index in time without significant losses can be realized in doped solid-state materials such as Er3+ :Y2SiO5 crystal, to provide optical quantum storage.