Building a tube and keeping it in a near- vacuum state is simply too complicated and expensive, BamBrogan says, to make it worth trying.

Using parametric conversion induced by a Shapiro-type resonance, we produce and characterize a two-mode squeezed vacuum state in a sodium spin 1 Bose-Einstein condensate.

We characterize and compare noise spectra taken without squeezing and with squeezed vacuum states injected at varying quadrature angles.