  We analyze the local density of states (LDOS) of heterostructures consisting
of alternating ferromagnet, $F$, and superconductor, $S$, layers. We consider
structures of the $SFS$ and $SFSFSFS$ type, with thin nanometer scale $F$ and
$S$ layers, within the ballistic regime. The spin-splitting effects of the
ferromagnet and the mutual coupling between the $S$ regions, yield several
nontrivial stable and metastable pair amplitude configurations, and we find
that the details of the spatial behavior of the pair amplitude govern the
calculated electronic spectra. These are reflected in discernible signatures of
the LDOS. The roles that the magnetic exchange energy, interface scattering
strength, and the Fermi wavevector mismatch each have on the LDOS for the
different allowed junction configurations, are systematically investigated.
