title: Aberrations of curved zone plates and Fresnel lenses.
abstract: The generalization of zone plates and Fresnel lenses from the usual flat surfaces to curved surfaces is discussed. It is shown that, although Abbe's sine law applies to zone plates but not to Fresnel lenses, both can yield single-element aplanats if formed on a curved surface. Third-order aberration formulas are given.
authors.forename: W A
authors.initials: WA
authors.lastname: Kleinhans