Navarro-Cia, M;
Wu, J;
Liu, H;
Mitrofanov, O;
(2016)
Generation of radially-polarized terahertz pulses for coupling into coaxial waveguides.
Scientific Reports
, 6
, Article 38926. 10.1038/srep38926.
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Wu-J_Generation of radially-polarized terahertz pulses_.pdf - Published Version Download (1MB) |
Abstract
Coaxial waveguides exhibit no dispersion and therefore can serve as an ideal channel for transmission of broadband THz pulses. Implementation of THz coaxial waveguide systems however requires THz beams with radially-polarized distribution. We demonstrate the launching of THz pulses into coaxial waveguides using the effect of THz pulse generation at semiconductor surfaces. We find that the radial transient photo-currents produced upon optical excitation of the surface at normal incidence radiate a THz pulse with the field distribution matching the mode of the coaxial waveguide. In this simple scheme, the optical excitation beam diameter controls the spatial profile of the generated radially-polarized THz pulse and allows us to achieve efficient coupling into the TEM waveguide mode in a hollow coaxial THz waveguide. The TEM quasi-single mode THz waveguide excitation and non-dispersive propagation of a short THz pulse is verified experimentally by time-resolved near-field mapping of the THz field at the waveguide output.
| Type: | Article |
|---|---|
| Title: | Generation of radially-polarized terahertz pulses for coupling into coaxial waveguides |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1038/srep38926 |
| Publisher version: | http://doi.org/10.1038/srep38926 |
| Language: | English |
| Additional information: | Copyright © 2017 The Author(s). All rights reserved. This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
| Keywords: | Electrical and electronic engineering, Semiconductors, Terahertz optics, Ultrafast photonics |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Electronic and Electrical Eng |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1536156 |
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