Spontaneous parametric down conversion in a doubly resonant one-dimensional photonic crystal Introini, Viola ; Steel, M. J. ; Sipe, J. E. ; Helt, L. G. ; Liscidini, Marco Abstract Publication: Optics Letters Pub Date: March 2020 DOI: 10.1364/OL.385741 Bibcode: 2020OptL...45.1244I