Noiseless phase quadrature amplification via electro-optic feed-forward
  Theoretical results are presented which show that noiseless phase quadrature amplification is possible, and limited experimentally only by the efficiency of the phase detection system. Experimental results obtained using a Nd:YAG laser show a signal gain of 10dB and a signal transfer ratio of T_s=0.9. This result easily exceeds the standard quantum limit for signal transfer. The results also explicitly demonstrate the phase sensitive nature of the amplification process. 
Ben C. Buchler, Elanor H. Huntington, Timothy C. Ralph