title: Limitations of superoscillation filters in microscopy applications.
abstract: The idea of superresolving pupil filters comes from the concept of superoscillations that may occur in regions of a band-limited signal with small amplitude having oscillations faster than the fastest Fourier component of the signal. In optical microscopy, superresolution can be achieved by appropriate design of pupil functions where the angular aperture determines the ultimate focal spot smaller than the Abbe diffraction limit outside the evanescent field region. The angular aperture cannot be increased indefinitely and the huge sidelobes cannot be avoided that are present in superresolving filters. The limitations of using such kind of filters in microscopy applications are discussed through computational examples.
authors.affiliation: University of Eastern Finland, Department of Physics and Mathematics, P.O. Box 111, FI-80101 Joensuu, Finland. heikki.j.hyvarinen@uef.fi
authors.forename: Heikki J
authors.initials: HJ
authors.lastname: Hyvärinen
authors.forename: Shakil
authors.initials: S
authors.lastname: Rehman
authors.forename: Jani
authors.initials: J
authors.lastname: Tervo
authors.forename: Jari
authors.initials: J
authors.lastname: Turunen
authors.forename: Colin J R
authors.initials: CJ
authors.lastname: Sheppard
mesh_terms: D008853:Microscopy / Q000379:methods*; D055620:Optical Phenomena