Improvement of Terahertz Photoconductive Antenna using Optical Antenna Array of ZnO Nanorods

Autor: Mohammad Neshat, Mohammadreza Kolahdouz, Seyed Ehsan Hosseininejad, Mohammad Bashirpour, Matin Forouzmehr
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Scientific Reports, Vol 9, Iss 1, Pp 1-8 (2019)
Scientific Reports
ISSN: 2045-2322
DOI: 10.1038/s41598-019-38820-3
Popis: An efficient terahertz (THz) photoconductive antenna (PCA), as a major constituent for the generation or detection of THz waves, plays an essential role in bridging microwave-to-photonic gaps. Here, we propose an impressive approach comprising the use of arrayed zinc oxide nanorods (ZnO NRs) as an optical nanoantenna over an anti-reflective layer (silicon nitride) in the antenna gap to boost the photocurrent and consequently the THz signal. The numerical approach applied in investigating the optical behavior of the structure, demonstrates a significant field enhancement within the LT-GaAs layer due to the optical antenna performing simultaneously as a concentrator and an antireflector which behaves as a graded-refractive index layer. ZnO NRs have been fabricated on the PCA gap using the hydrothermal method as a simple, low cost and production compatible fabrication method compared to other complex methods used for the optical nanoantennas. Compared to the conventional PCA with a traditional antireflection coating, the measured THz power by time domain spectroscopy (TDS) is increased more than 4 times on average over the 0.1–1.2 THz range.
Databáze: OpenAIRE
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