  We propose the implementation of a light source, which can deterministically
generate a rich variety of multi-mode quantum states. The desired states are
encoded in the collective population of different ground hyperfine states of an
atomic ensemble and converted to multi-mode photonic states by excitation to
optically excited levels followed by cooperative spontaneous emission. Among
our examples of applications, we demonstrate how two-photon entangled states
can be prepared and implemented in a protocol for reference frame free quantum
key distribution and how one-dimensional as well as higher-dimensional cluster
states can be produced.
