Reducing number fluctuations of ultracold atomic gases via dispersive   interrogation
  We have used nondestructive laser probing to follow the central density evolution of a trapped atomic cloud during forced evaporative cooling. This was achieved in a heterodyne dispersive detection scheme. We propose to use this as a precursor measurement for predicting the atom number subsequent to evaporation and provide a simple experimental demonstration of the principle leading to a conditional reduction of classical number fluctuations. 
Bianca J. Sawyer, Amita B. Deb, Thomas McKellar and Niels   Kj{\ae}rgaard
cond-mat.quant-gas physics.atom-ph