Fast polarimetry system for the application to spin quantum   non-demolition measurement
  We report the development of a fast pulse polarimeter for the application to quantum non-demolition measurement of atomic spin (Spin QND). The developed system was tunable to the atomic resonance of ytterbium atom and has narrow laser linewidth suitable for spin QND. Using the developed polarimeter, we successfully demonstrated the measurement of the vacuum noise, with 10^6 to 10^7 photon number per pulse. 
M. Takeuchi, T. Takano, S. Ichihara, A. Yamaguchi, M. Kumakura, T.   Yabuzaki, Y. Takahashi