Quantum correlations and non-demolition measurements using two-photon non-linearities in optical cavities

Abstract : We present an analysis of the coupling of the quantum fluctuations of two initially independent laser beams, using a two-photon non-linear medium inside an optical cavity. Depending on the detuning of the lasers relative to the cavity resonance, either quantum non-demolition measurement, or squeezing of the sum or the difference of the input intensities can be obtained.