  A process which strongly amplifies both quadrature amplitudes of an
oscillatory signal necessarily adds noise. Alternatively, if the information in
one quadrature is lost in phase-sensitive amplification, it is possible to
completely reconstruct the other quadrature. Here we demonstrate such a nearly
perfect phase-sensitive measurement using a cavity optomechanical scheme,
characterized by an extremely small noise less than 0.2 quanta. We also observe
microwave radiation strongly squeezed by 8 dB below vacuum. A source of bright
squeezed microwaves opens up applications in manipulations of quantum systems,
and noiseless amplification can be used even at modest cryogenic temperatures.
