Spatial and temporal properties of parametric fluorescence around degeneracy in a type I LBO crystal

We present a theoretical and experimental study of the spatio-temporal prop erties of the spontaneous parametric emission generated in a type I LBO cry stal around degeneracy. The number of quasi-phase-matched modes is shown to be equal to the number of spatio-temporal degrees of freedom of the image that can be parametrically amplified. From this number, we demonstrate the possibility of predicting the total number of photons generated by parametr ic fluorescence. Correlation is observed between spatial intensity fluctuat ions corresponding to pairs of signal-idler modes.