Hong, B orcid.org/0000-0002-8033-5438, Chudpooti, N, Akkaraekthalin, P et al. (3 more authors) (2018) Investigation of Electromagnetic Mode Transition and Filtering of an Asymptotically Single-mode Hollow THz Bragg Fibre. Journal of Physics D: Applied Physics, 51 (30). ARTN 305101. ISSN 0022-3727
Abstract
The mechanism for electromagnetic (EM) mode transition and filtering in an asymptotically single-HE11-mode hollow THz Bragg fibre is investigated. We designed, fabricated, and measured Bragg fibres with an asymptotically single-mode pattern, achieving measured signal propagation loss of better than 3 dB m−1 at 0.265 THz and with an operating frequency range from 0.246 to 0.276 THz. Mode transition and filtering effects are both verified by 3D full-wave simulations using measured material properties, with geometrical parameters extracted from the fabricated Bragg fibre prototypes. By optimizing the coupling efficiency between the free-space Gaussian beam and the guided Bessel function mode, the optimum distance of mode transition from the Gaussian-beam excitation into the guided mode is calculated to be ~13.7 free-space wavelengths in our fibre, to ensure fast EM-field convergence to the desired asymptotically single-mode mode pattern in the Bragg fibre. After this mode transition region, the electric field amplitude ratio between the desired HE11 mode and the main competing HE12 mode is approximately 7 times, with the HE12 mode attenuation being more than 10 dB m−1 larger than the fundamental HE11 mode; the results indicate that our fibre is one of the best candidates for low-loss asymptotically single-mode terahertz signal interconnections.
Metadata
Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2018 IOP Publishing Ltd. This is an author produced version of a paper published in Journal of Physics D: Applied Physics. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Bragg fibre; electromagnetic propagation; single-mode; mode transition; modal-filtering effect |
Dates: |
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Institution: | The University of Leeds |
Depositing User: | Symplectic Publications |
Date Deposited: | 14 Jun 2018 14:13 |
Last Modified: | 02 Jul 2019 00:41 |
Status: | Published |
Publisher: | IOP Publishing |
Identification Number: | https://doi.org/10.1088/1361-6463/aaccaa |
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