title: Terahertz near-field vectorial imaging of subwavelength apertures and aperture arrays.
abstract: We present measurements of the complete terahertz (THz) electric near-field distribution, E(x), E(y) and E(z), in both the time- and frequency-domains, for subwavelength apertures and subsections of subwavelength aperture arrays. Measuring the individual components of the THz near-field with subwavelength spatial resolution, as they emerge from these structures, illustrates how the field interacts with the apertures. We observe the small but measurable y- and z-components of the electric field for both single apertures and arrays. Resonant contributions, attributed to Bloch modes, are detected and we observe the presence of a longitudinal field component, E(z), within the different array apertures, which can be attributed to a diffractive effect. These measurements illustrate in detail the individual THz field components emerging from subwavelength apertures and provide a direct measure of two important mechanisms that contribute to the net transmission of light through arrays.
authors.affiliation: Delft University of Technology, Faculty of Applied Sciences, Department of Imaging Science and Technology, Optics Research Group, Lorentzweg 1, 2628 CJ Delft, The Netherlands. J.R.Knab@tudelft.nl
authors.forename: J R
authors.initials: JR
authors.lastname: Knab
authors.forename: A J L
authors.initials: AJ
authors.lastname: Adam
authors.forename: M
authors.initials: M
authors.lastname: Nagel
authors.forename: E
authors.initials: E
authors.lastname: Shaner
authors.forename: M A
authors.initials: MA
authors.lastname: Seo
authors.forename: D S
authors.initials: DS
authors.lastname: Kim
authors.forename: P C M
authors.initials: PC
authors.lastname: Planken
mesh_terms: D003198:Computer Simulation; D004867:Equipment Design / Q000379:methods; D008422:Materials Testing; D055095:Optics and Photonics; D012031:Refractometry / Q000295:instrumentation* / Q000379:methods; D012825:Silicon / Q000737:chemistry; D020349:Surface Plasmon Resonance / Q000379:methods; D055068:Terahertz Spectroscopy / Q000379:methods*
chemical_list: D012825:Silicon