2-PHOTON (SQUEEZED) LIGHT - CLASSICAL AND QUANTUM EFFECTS

Several quantum-optical experiments, using a parametric down-converter as a light source, are analysed by means of a model which permits the transition to the classical limit, so that the classical and quantum features could be discriminated. It is shown that all considered "two-photon" interference phenomena could be observed with the classical squeezed light, obtained by amplification of chaotic light in a down-converter. The quantum character belongs not to the interference phenomena itself, but to the initial field, which reveals itself only in the low level of the background noise, i.e. in the visibility of the effect. The absolute magnitude is larger in the classical limit. © 1990.