Large near-to-far field spectral shifts for terahertz resonances

Bhattacharya, A., Georgiou, G. , Sawallich, S., Matheisen, C., Nagel, M. and Gómez Rivas, J. (2016) Large near-to-far field spectral shifts for terahertz resonances. Physical Review B, 93(3), 035438. (doi: 10.1103/PhysRevB.93.035438)

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Abstract

We have performed far-field extinction measurements and near electric field measurements on gold bowtie antennas resonant at THz frequencies. These measurements show a very large shift between the resonant frequencies of the near-field and the far-field spectra. We use the established damped-driven harmonic oscillator model for resonators to model the far-field response of the antennas from the near-field spectrum and show that there is a large discrepancy between the predicted and measured far-field response. We were able to explain this discrepancy by improving the oscillator model with a Fano model. This large shift makes the prediction of the near-field response of resonant structures at THz frequencies very imprecise, provided that only information of the far-field response is available and establishes the necessity of measuring near fields for a correct and accurate characterization of these structures.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Georgiou, Dr Giorgos
Authors: Bhattacharya, A., Georgiou, G., Sawallich, S., Matheisen, C., Nagel, M., and Gómez Rivas, J.
College/School:College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
Journal Name:Physical Review B
Publisher:American Physical Society
ISSN:2469-9950
ISSN (Online):2469-9969
Published Online:21 January 2016

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