title: Spatial filters for replicating images.
abstract: The conditions for self-imaging, longitudinal periodicity are relaxed to demand image replication only along the optical axis. Lateral periodicity in the square of the radius, in the spatial-frequency domain, is necessary and sufficient for image replication along the optical axis. This formulation allows one to employ any zone plate as a spatial filter that creates self-replicating images of a given object, under either coherent or incoherent illumination.
authors.forename: J
authors.initials: J
authors.lastname: Ojeda-Castañeda
authors.forename: P
authors.initials: P
authors.lastname: Andrés
authors.forename: E
authors.initials: E
authors.lastname: Tepíchin