  We present a scheme to obtain the coherently enhanced Raman scattering in
atomic vapor which is induced by a spin wave initially written by a weak write
laser. The enhancement of Raman scattering is dependent on the number and the
spatial distribution of the flipped atoms generated by the weak write laser.
Such an enhanced Raman scattering may have practical applications in quantum
information, nonlinear optics and laser spectroscopy because of its simplicity.
