Properties of entangled photon pairs generated in periodically poled nonlinear crystals

Using a rigorous quantum model a comprehensive study of physical properties of entangled photon pairs generated in spontaneous parametric down-conversion in chirped periodically-poled crystals is presented. Spectral, temporal, as well as spatial characteristics of photon pairs are analyzed. Spectral bandwidths, photon-pair flux, and entanglement area can be effectively controlled by chirping. Quantification of entanglement between photons in a pair is given. Splitting of entanglement area in the transverse plane accompanied by spectral splitting has been revealed. Using the model temperature dependencies of the experimental intensity profiles reported in literature have been explained.