Mohandas, RA;
Freeman, JR;
Natrella, M;
Rosamond, MC;
Ponnampalam, L;
Fice, MJ;
Seeds, AJ;
... Dean, P; + view all
(2017)
Terahertz generation mechanism in nanograting electrode photomixers on Fe-doped InGaAsP.
Optics Express
, 25
(9)
pp. 10177-10188.
10.1364/OE.25.010177.
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Abstract
We report the generation mechanism associated with nano-grating electrode photomixers fabricated on Fe-doped InGaAsP substrates. Two different emitter designs incorporating nano-gratings coupled to the same broadband antenna were characterized in a continuous-wave terahertz (THz) frequency system employing telecommunications wavelength lasers for generation and coherent detection. The current-voltage characteristics and THz emission bandwidth of the emitters is compared for different bias polarities and optical polarisations. The THz output from the emitters is also mapped as a function of the position of the laser excitation spot for both continuous-wave and pulsed excitation. This mapping, together with full-wave simulations of the structures, confirms the generation mechanism to be due to an enhanced optical electric field at the grating tips resulting in increased optical absorption, coinciding with a concentration of the electrostatic field.
| Type: | Article |
|---|---|
| Title: | Terahertz generation mechanism in nanograting electrode photomixers on Fe-doped InGaAsP |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1364/OE.25.010177 |
| Publisher version: | http://doi.org/10.1364/OE.25.010177 |
| Language: | English |
| Additional information: | Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. |
| Keywords: | Science & Technology, Physical Sciences, Optics, WAVE GENERATION, OUTPUT POWER, LASER, GAAS, PERFORMANCE, TECHNOLOGY, EMISSION, DEVICES, SYSTEM, DIODE |
| 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/1558662 |
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