Conditional preparation of a quantum state in the continuous variable regime: generation of a sub-Poissonian state from twin beams

Julien Laurat (1) , Thomas Coudreau (1) , Nicolas Treps (1) , Agnès Maître (1) , Claude Fabre (1)

1 LKB (Jussieu) - Laboratoire Kastler Brossel

We report the first experimental demonstration of conditional preparation of a non classical state of light in the continuous variable regime. Starting from a non degenerate OPO which generates above threshold quantum intensity correlated signal and idler "twin beams", we keep the recorded values of the signal intensity only when the idler falls inside a band of values narrower than its standard deviation. By this very simple technique, we generate a sub-Poissonian state 4.4dB below shot noise from twin beams exhibiting 7.5dB of noise reduction in the intensity difference.

Mots clés: Quantum Optics; OPO; Squeezed states

Domaines: Physique Quantique [quant-ph]

Julien Laurat, Thomas Coudreau, Nicolas Treps, Agnès Maître, Claude Fabre. Conditional preparation of a quantum state in the continuous variable regime: generation of a sub-Poissonian state from twin beams. Physical Review Letters, 2003, 91, pp.213601. ⟨hal-00000312v2⟩