  Under certain conditions, a transparent photonic band can be designed into a
one-dimensional metallodielectric nanofilm structure. Unlike conventional pass
bands in photonic crystals, where the finite thickness of the structure affects
the transmission of electromagnetic fields having frequency within the pass
band, the properties of the transparent band are almost unaffected by the
finite thickness of the structure. In other words, an incident field at a
frequency within the transparent band exhibits 100% transmission independent of
the number of periods of the structure. The transparent photonic band
corresponds to excitation of pure eigenstate modes across the entire Bloch band
in structures possessing mirror symmetry. The conditions to create these modes
and thereby to lead to a totally transparent band phenomenon are discussed.
