On the relationship between pump chirp and single-photon chirp in   spontaneous parametric downconversion
  We study the chronocyclic character, i.e. the joint temporal and spectral properties, of the single-photon constituents of photon pairs generated by spontaneous parametric down conversion. In particular we study how single photon properties, including purity and single-photon chirp, depend on photon pair properties, including the type of signal-idler spectral and correlations and the level of pump chirp. 
X. Sanchez-Lozano, A. B. U'Ren, J. L. Lucio
quant-ph