  We have developed a novel multiscale computational scheme to describe coupled
dynamics of light electromagnetic field with electrons and atoms in crystalline
solids, where first-principles molecular dynamics based on time-dependent
density functional theory is used to describe the microscopic dynamics. The
method is applicable to wide phenomena in nonlinear and ultrafast optics. To
show usefulness of the method, we apply it to a pump-probe measurement of
coherent phonon in diamond where a Raman amplification takes place during the
propagation of the probe pulse.
