Open AccessEnhanced infrared spectroscopy using small-gap antennas prepared with two-step evaporation nanosphere lithography
Author(s) -
Jón Mattis Hoffmann,
Holger Janßen,
Dmitry N. Chigrin,
Thomas Taubner
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.014425
Subject(s) - materials science , optics , evaporation , antenna (radio) , infrared spectroscopy , spectroscopy , infrared , lithography , optoelectronics , substrate (aquarium) , absorption (acoustics) , absorption spectroscopy , physics , telecommunications , oceanography , quantum mechanics , computer science , composite material , thermodynamics , geology
We use nanosphere lithography in combination with two evaporation steps to create bow-tie like infrared antennas with small gaps. The angle of the sample with respect to the evaporation source is changed between two evaporation steps resulting in a displacement of the respective antenna arrays and, therefore, in decreased antenna-gaps. Furthermore, we demonstrate the gap-dependency of surface-enhanced infrared absorption (SEIRA) spectroscopy using the absorption band of the natural SiO(2)-layer of the silicon substrate and antennas with different gap size. A multi-oscillator-model is used to describe the Fano-like spectral coupling of the antenna resonances with the SiO(2) absorption band.