title: Measuring different types of transverse momentum correlations in the biphoton's Fourier plane.
abstract: In this Letter, we present a theoretical and experimental study about the spatial correlations of paired photons generated by Type II spontaneous parametric down-conversion. In particular, we show how these correlations can be positive or negative, depending on the direction in which the far-field plane is scanned and the polarization postselected. Our results provide a straightforward way to observe different kind of correlations that complement other well-known methods to tune the spatial correlations of paired photons.
authors.forename: Omar
authors.initials: O
authors.lastname: Calderón-Losada
authors.forename: Jefferson
authors.initials: J
authors.lastname: Flórez
authors.forename: Juan P
authors.initials: JP
authors.lastname: Villabona-Monsalve
authors.forename: Alejandra
authors.initials: A
authors.lastname: Valencia