  Photon echo schemes are excellent candidates for high efficiency coherent
optical memory. They are capable of high-bandwidth multi-pulse storage, pulse
resequencing and have been shown theoretically to be compatible with quantum
information applications. One particular photon echo scheme is the gradient
echo memory (GEM). In this system, an atomic frequency gradient is induced in
the direction of light propagation leading to a Fourier decomposition of the
optical spectrum along the length of the storage medium. This Fourier encoding
allows precision spectral manipulation of the stored light. In this letter, we
show frequency shifting, spectral compression, spectral splitting, and fine
dispersion control of optical pulses using GEM.
