Phase resolved near-field mode imaging for the design of frequency-selective surfaces

By: Edward C. Kinzel, James C. Ginn, Robert L. Olmon, David J. Shelton, Brian A. Lail, Igal Brener, Michael B. Sinclair, Markus B. Raschke, and Glenn D. Boreman

Optics Express 20, 11986 (2012)

Frequency-selective surfaces (FSS) are a class of metasurfaces with engineered reflectance, absorbance, and transmittance behavior. We study an array of metallic crossed dipole FSS elements in the infrared using interferometric scattering-type scanning near-field optical microscopy (s-SNOM). We resolve the dependence of the near-field phase on the dimensions of the elements and compare with numerical models. The combined phase and amplitude information of the underlying near-field mode distribution compared to conventional far-field absorption spectroscopy greatly improves the targeted design of frequency-selective surfaces.