title: Comment on "Reconstruction algorithm for high-numerical-aperture holograms with diffraction-limited resolution".
abstract: We comment on a recent Letter by Zhang et al. [Opt. Lett. 31, 1633 (2006)] in which the authors proposed a reconstruction algorithm for high-numerical-aperture (NA) holograms. Such an algorithm has been available for in-line holography for more than a decade. The authors' "achievement" of high NA for digital in-line holography, NA=0.17, is below what was reported already several years ago (NA=0.30) and is considerably lower than what is routinely achieved now. We present reconstructions of holograms acquired with NAs above 0.4 in which we show maximal achievable resolution.
authors.affiliation: Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada. jigarcia@fizz.phys.dal.ca
authors.forename: J
authors.initials: J
authors.lastname: Garcia-Sucerquia
authors.forename: D C
authors.initials: DC
authors.lastname: Alvarez-Palacio
authors.forename: M H
authors.initials: MH
authors.lastname: Jericho
authors.forename: H J
authors.initials: HJ
authors.lastname: Kreuzer