Propagation of Squeezed Vacuum under Electromagnetically Induced   Transparency
  We experimentally and theoretically analyze the transmission of continuous-wave and pulsed squeezed vacuum through rubidium vapor under the conditions of electromagnetically induced transparency. Frequency- and time-domain homodyne tomography is used to measure the quadrature noise and reconstruct the quantum states of the transmitted light. A simple theoretical model explains the spectrum and degradation of the transmitted squeezing with high precision. 
Eden Figueroa, Mirko Lobino, Dmitry Korystov, Juergen Appel, A. I.   Lvovsky