Sub shot noise phase quadrature measurement of intense light beams
  We present a setup to perform sub shot noise measurements of the phase quadrature for intense pulsed light without the use of a separate local oscillator. A Mach--Zehnder interferometer with an unbalanced arm length is used to detect the fluctuations of the phase quadrature at a single side band frequency. Using this setup, the non--separability of a pair of quadrature entangled beams is demonstrated experimentally. 
O. Gl\"ockl, U. L. Andersen, S. Lorenz, Ch. Silberhorn, N. Korolkova,   G. Leuchs