  Double-layer quantum Hall systems at Landau level filling factor $\nu=1$ have
a broken symmetry ground state with spontaneous interlayer phase coherence and
a gap between symmetric and antisymmetric subbands in the absence of interlayer
tunneling. We examine the influence of quantum fluctuations on the spectral
function of the symmetric Green's function, probed in optical absorption
experiments (cond-mat/9809373). We find that as the maximum layer separation at
which the $\nu=1$ quantum Hall effect occurs is approached, absorption in the
lowest Landau level grows in strength. Detailed line shapes for this absorption
are evaluated and related to features in the system's collective excitation
spectrum.
