  We show that the AC-Stark shift (light-shift) is a powerful and versatile
tool to control the emission of a photon-echo in the context of optical
storage. As a proof-of-principle, we demonstrate that the photon-echo
efficiency can be fully modulated by applying light-shift control pulses in an
erbium doped solid. The control of the echo emission is attributed to the
spatial gradient induced by the light-shift beam.
