  We experimentally demonstrate dressed multi-wave mixing (MWM) and the
reflection of the probe beam due to electromagnetically induced absorption
(EIA) grating can coexist in a five-level atomic ensemble. The reflection is
derived from the photonic band gap (PBG) of EIA grating, which is much broader
than the PBG of EIT grating. Therefore, EIA-type PBG can reflect more energy
from probe than EIT-type PBG does, which can effectively affect the MWM signal.
The EIA-type as well as EIT-type PBG can be controlled by multiple parameters
including the frequency detunings, propagation angles and powers of the
involved light fields. Also, the EIA-type PBG by considering both the linear
and third-order nonlinear refractive indices is also investigated. The
theoretical analysis agrees well with the experimental results. This
investigation has potential applications in all-optical communication and
information processing.
