eprintid: 10189665
rev_number: 7
eprint_status: archive
userid: 699
dir: disk0/10/18/96/65
datestamp: 2024-03-25 11:10:05
lastmod: 2024-03-25 11:10:05
status_changed: 2024-03-25 11:10:05
type: article
metadata_visibility: show
sword_depositor: 699
creators_name: Seddon, James
creators_name: Hale, Lucy
creators_name: Jung, Hyunseung
creators_name: Norman, Sarah
creators_name: Brener, Igal
creators_name: Seeds, Alwyn
creators_name: Renaud, Cyril
creators_name: Mitrofanov, Oleg
title: Continuous wave terahertz detection using 1550 nm pumped nonlinear photoconductive GaAs metasurfaces
ispublished: pub
divisions: UCL
divisions: B04
divisions: C05
divisions: F46
note: © The Author(s), 2024. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. https://creativecommons.org/licenses/by/4.0/
abstract: Terahertz (THz) continuous wave (CW) spectroscopy systems can offer extremely high spectral resolution over the THz band by photo-mixing high-performance telecommunications-band (1530-1565 nm) lasers. However, typical THz CW detectors in these systems use narrow band-gap photoconductors, which require elaborate material growth and generate relatively large detector noise. Here we demonstrate that two-step photon absorption in a nano-structured low-temperature grown GaAs (LT-GaAs) metasurface which enables switching of photoconductivity within approximately one picosecond. We show that LT-GaAs can be used as an ultrafast photoconductor in CW THz detectors despite having a bandgap twice as large as the telecommunications laser photon energy. The metasurface design harnesses Mie modes in LT GaAs resonators, whereas metallic electrodes of THz detectors can be designed to support an additional photonic mode, which further increases photoconductivity at a desired wavelength.
date: 2024-03-11
date_type: published
publisher: Optica Publishing Group
official_url: https://doi.org/10.1364/OE.517422
oa_status: green
full_text_type: pub
language: eng
primo: open
primo_central: open_green
verified: verified_manual
elements_id: 2261395
doi: 10.1364/OE.517422
lyricists_name: Seddon, James
lyricists_id: SEDDO19
actors_name: Seddon, James
actors_id: SEDDO19
actors_role: owner
full_text_status: public
publication: Optics Express
volume: 32
number: 6
pagerange: 9809-9819
issn: 1094-4087
citation:        Seddon, James;    Hale, Lucy;    Jung, Hyunseung;    Norman, Sarah;    Brener, Igal;    Seeds, Alwyn;    Renaud, Cyril;           Seddon, James;  Hale, Lucy;  Jung, Hyunseung;  Norman, Sarah;  Brener, Igal;  Seeds, Alwyn;  Renaud, Cyril;  Mitrofanov, Oleg;   - view fewer <#>    (2024)    Continuous wave terahertz detection using 1550 nm pumped nonlinear photoconductive GaAs metasurfaces.                   Optics Express , 32  (6)   pp. 9809-9819.    10.1364/OE.517422 <https://doi.org/10.1364/OE.517422>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/10189665/1/oe-32-6-9809.pdf