Demonstration of a bright and compact source of tripartite nonclassical light

We experimentally demonstrate the nonclassical photon number correlations expected in tripartite continuous-variable states obtained by parametric processes. Our scheme involves a single nonlinear crystal, where two interlinked parametric interactions take place simultaneously, and represents a bright and compact source of a sub-shot-noise tripartite light field. We analyze the effects of the pump intensities on the numbers of detected photons and on the amount of noise reduction in some detail, thus demonstrating a good agreement between the experimental data and a single-mode theoretical description. © 2008 The American Physical Society.