Optomechanical Cooling of a Macroscopic Oscillator by Homodyne Feedback
  We propose a simple optomechanical model in which a mechanical oscillator quadrature could be "cooled" well below its equilibrium temperature by applying a suitable feedback to drive the orthogonal quadrature by means of the homodyne current of the radiation field used to probe its position. 
Stefano Mancini, David Vitali and Paolo Tombesi (Dip. Matematica e   Fisica, Univ. Camerino, Italy)