  We use a coherent Bragg diffraction method to impart an external momentum to
ultracold bosonic atoms trapped in a one-dimensional optical lattice. This
method is based on the application of a single light pulse, with conditions
where scattering of photons can be resonantly amplified by the atomic density
grating. An oscillatory behavior of the momentum distribution resulting from
the time evolution in the lattice potential is then observed. By measuring the
oscillating frequencies, we extract multi-band energy structures of
single-particle excitations with zero pseudo-momentum transfer for a wide range
of lattice depths. The excitation energy structures reveal the interaction
effect through the whole range of lattice depth.
