K. Edamatsu et al., 2-PHOTON EXCITATION OF 3-LEVEL ATOMS IN A SQUEEZED VACUUM, Progress in crystal growth and characterization of materials, 33(1-3), 1996, pp. 335-338
We have investigated the two-photon transition (6S(1/2)-->6P(3/2)-->6D
(5/2)) of trapped atomic Cesium for excitation by squeezed vacuum gene
rated via nondegenerate (two-color) parametric down conversion, The ex
citation rate exhibits a non-quadratic dependence of aI(2) + bI on the
incident photon flux (I), reflecting the nonclassical correlations of
the squeezed vacuum field.