Enhanced terahertz radiation of photoconductive antenna fabricated on GaAs-on-sapphire
AffiliationUniv Arizona, Dept Elect & Comp Engn
Univ Arizona, Wyant Coll Opt Sci
MetadataShow full item record
PublisherAMER INST PHYSICS
CitationAIP Advances 9, 125234 (2019); https://doi.org/10.1063/1.5127877
Rights© 2019 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
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AbstractThe terahertz (THz) radiation properties of a photoconductive antenna (PCA) fabricated on a GaAs-on-sapphire (GoS) substrate are reported at sub-THz band. The GaAs layer with a thickness of approximately 1 µm was directly deposited on a sapphire wafer by means of molecular beam epitaxy. A butterfly-shaped antenna structure was then fabricated on the GoS substrate by photolithography, and the device was tested as the emitter of an in-house built THz time-domain spectrometer. The performance of this antenna was compared with a commercial one, which had an identical antenna structure but was fabricated on low-temperature-grown GaAs (LT-GaAs). The results showed that the GoS-based PCA radiated an enhanced THz field, which could be as much as 1.9 times that of the LT-GaAs-based PCA, indicating that GoS could be a promising photoconductive material. In addition, the optical transparency of the sapphire substrate allows the device to be illuminated from the backside, which is crucial for THz near-field imaging applications where the sample is usually in close proximity to the front surface of the PCA device.
NoteOpen access article
VersionFinal published version
SponsorsNational Science Foundation Major Research Instrument Program ; United States Department of Defense Air Force Office of Scientific Research (AFOSR) [FA9550-12-1-0003]; NSF-ERC Center for Integrated Access Networks (CIAN)