  We suggest an all-optical quantum memory scheme which is based on the
off-resonant Raman interaction of a signal quantum field and a strong control
field in a three-level atomic medium in the case, when the control field has a
spatially varying frequency across the beam, called a spatial chirp. We show
that the effect of such a spatial chirp is analogous to the effect of a
controllable reversible inhomogeneous broadening (CRIB) of the atomic
transition used in the gradient echo memory (GEM) scheme. However, the proposed
scheme does not require temporal modulation of the control field or the atomic
levels, and can be realized without additional electric or magnetic fields. It
means that materials demonstrating neither linear Stark nor Zeeman effects can
be used and/or materials which are placed in specific external fields remain
undisturbed.
