The data density that can be resolved in optical memories is limited b
y the inherent band-limited nature of optical systems. We show how a p
recoding technique used in serial communications, called partial respo
nse precoding, can be applied to parallel readout optical memories to
precompensate for the spatial data broadening that occurs as result of
this band limiting. We experimentally demonstrate a factor-of-15 impr
ovement in average worst-case contrast ratio and an order-of-magnitude
improvement in average contrast ratio. Over 50% more area was needed
to achieve the same contrast ratio in a system without precoding.