  Quantum fluids of light in a nonlinear planar microcavity can exhibit
antibunched photon statistics at short distances due to repulsive polariton
interactions. We show that, despite the weakness of the nonlinearity, the
antibunching signal can be amplified orders of magnitude with an appropriate
free-space optics scheme to select and interfere output modes. Our results are
understood from the unconventional photon blockade perspective by analyzing the
approximate Gaussian output state of the microcavity. In a second part, we
illustrate how the temporal and spatial profile of the density-density
correlation function of a fluid of light can be reconstructed with free-space
optics. Also here the nontrivial (anti)bunching signal can be amplified
significantly by shaping the light emitted by the microcavity.
