  We show that inducing sidebands in the emission of a single emitter into a
one dimensional waveguide, together with a dissipative re-pumping process, a
photon field is cooled down to a squeezed vacuum. Our method does not require
to be in the strong coupling regime, works with a continuum of propagating
field modes and it may lead to sources of tunable multimode squeezed light in
circuit QED systems.
