Experimental realization of a quantum optical tap

Jean-Philippe Poizat (1) , Philippe Grangier (1)

1 Laboratoire Charles Fabry de l'Institut d'Optique / Optique quantique

We have realized a system which is able to read out information encoded on the amplitude of a laser beam without degrading the signal-to-noise ratio of the carrier. This has been implemented using the two-photon cross-phase-modulation effect of a three-level system in a sodium atomic beam located in a doubly resonant optical cavity. We have achieved an improvement by a factor of 1.35 of the overall information transer compared to any classical optical tap, where a perfect quantum duplicator would reach the ideal value of 2.

Domains: Physics [physics]; Quantum Physics [quant-ph]

Jean-Philippe Poizat, Philippe Grangier. Experimental realization of a quantum optical tap. Physical Review Letters, 1993, 70, pp.271-274. ⟨10.1103/PhysRevLett.70.271⟩. ⟨hal-00559077⟩