title: Near-field spectroscopic properties of complementary gold nanostructures: applicability of Babinet's principle in the optical region.
abstract: We examine the far-field and near-field properties of complementary screens made of nanostructured gold thin films, a rectangular nanowire and a nanovoid, using an aperture-type scanning near-field optical microscope and electromagnetic field calculations, and discuss the applicability of Babinet's principle in the optical region. The far-field transmission spectra of the complementary screens are considerably different from each other. On the other hand, genuine near-field extinction spectra exhibit nearly complementary characteristics. The spatial features of the observed near-field images for the complementary screens show little correlation. We have found from the Fourier analysis of the simulated images that high spatial-frequency components of the electromagnetic fields show mutual spatial correlation. These results suggest that Babinet's principle is applicable to the high spatial-frequency components of electromagnetic fields for the complementary screens.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Mizobata
authors.forename: Kosei
authors.initials: K
authors.lastname: Ueno
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Misawa
authors.forename: Hiromi
authors.initials: H
authors.lastname: Okamoto
authors.forename: Kohei
authors.initials: K
authors.lastname: Imura