Siday, T;
Natrella, M;
Wu, J;
Liu, H;
Mitrofanov, O;
(2017)
Resonant terahertz probes for near-field scattering microscopy.
Optics Express
, 25
(22)
pp. 27874-27885.
10.1364/OE.25.027874.
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Abstract
We propose and characterize a scattering probe for terahertz (THz) near-field microscopy, fabricated from indium, where the scattering efficiency is enhanced by the dipolar resonance supported by the indium probe. The scattering properties of the probe were evaluated experimentally using THz time-domain spectroscopy (TDS), and numerically using the finite-difference time-domain (FDTD) method in order to identify resonant enhancement. Numerical measurements show that the indium probes exhibit enhanced scattering across the THz frequency range due to dipolar resonance, with a fractional bandwidth of 0.65 at 1.24 THz. We experimentally observe the resonant enhancement of the scattered field with a peak at 0.3 THz. To enable practical THz microscopy applications of these resonant probes, we also demonstrate a simple excitation scheme utilizing a THz source with radial polarization, which excites a radial mode along the length of the tip. Strong field confinement at the apex of the tip, as required for THz near-field microscopy, was observed experimentally.
| Type: | Article |
|---|---|
| Title: | Resonant terahertz probes for near-field scattering microscopy |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1364/OE.25.027874 |
| Publisher version: | https://doi.org/10.1364/OE.25.027874 |
| Language: | English |
| Additional information: | 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: | Science & Technology, Physical Sciences, Optics, OPTICAL MICROSCOPY, SPECTROSCOPY, RESOLUTION, PROPAGATION, DETECTOR, WAVES, WIRE, TIME |
| 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/10038297 |
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