  Multimode bright squeezed vacuum is a non-classical state of light hosting a
macroscopic photon number while offering promising capacity for encoding
quantum information in its spectral degree of freedom. Here, we employ an
accurate model for parametric downconversion in the high-gain regime and use
nonlinear holography to design quantum correlations of bright squeezed vacuum
in the frequency domain. We propose the design of quantum correlations over
two-dimensional lattice geometries that are all-optically controlled, paving
the way toward continuous-variable cluster state generation on an ultrafast
timescale. Specifically, we investigate the generation of a square cluster
state in the frequency domain and calculate its covariance matrix and the
quantum nullifier uncertainties, that exhibit squeezing below the vacuum noise
level.
