title: Stimulated emission tomography.
abstract: We identify a relation between the number of photon pairs generated by parametric fluorescence, through either spontaneous parametric down-conversion (SPDC) or spontaneous four-wave mixing, and the number generated by the corresponding stimulated process, respectively, either difference-frequency generation or stimulated four-wave mixing. On the basis of this very general result, we show that the characterization of SPDC sources of two-photon states in a given system can be performed solely by studying stimulated emission. We call this technique stimulated emission tomography (SET). We show that the number of photons detected in SET can be 9 orders of magnitude larger than the average number of coincidence counts in two-photon quantum state tomography. These results open the way to the study of sources of quantum-correlated photon pairs with unprecedented precision and unparalleled resolution.
authors.affiliation: Dipartimento di Fisica, Università degli Studi di Pavia, via Bassi 6, I-27100 Pavia, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Liscidini
authors.forename: J E
authors.initials: JE
authors.lastname: Sipe