title: Dispersion-based control of modal characteristics for parametric down-conversion in a multimode waveguide.
abstract: We report generation of near-infrared photon pairs in fundamental spatial modes via type-II spontaneous parametric down-conversion in a periodically poled potassium titanyl phosphate (KTiOPO(4)) nonlinear waveguide supporting multiple transverse modes. This demonstrates experimentally a versatile scheme for controlling the spatial characteristics of the produced nonclassical light based on exploitation of intermodal dispersion. The down-converted photons are characterized by the measurement of the beam quality factors in the heralded regime.
authors.affiliation: Faculty of Physics, University of Warsaw, ul. Hoża 69, 00-681 Warszawa, Poland. mkarp@fuw.edu.pl
authors.forename: Michał
authors.initials: M
authors.lastname: Karpiński
authors.forename: Czesław
authors.initials: C
authors.lastname: Radzewicz
authors.forename: Konrad
authors.initials: K
authors.lastname: Banaszek