Enhanced terahertz emission in a large-area photoconductive antenna through an array of tightly packed sapphire fibers

• Published in: Applied physics letters Vol. 124; no. 12
• Main Authors: Zenchenko, N. V., Lavrukhin, D. V., Galiev, R. R., Yachmenev, A. E., Khabibullin, R. A., Goncharov, Yu. G., Dolganova, I. N., Kurlov, V. N., Otsuji, T., Zaytsev, K. I., Ponomarev, D. S.
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 18-03-2024
• Subjects: Antenna arrays; Antennas; Emitters; Laser beams; Microlenses; Numerical prediction; Sapphire; Spectral emittance; Topology
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/5.0194236

Experimental observation of the enhanced terahertz (THz) emission in a large-area photoconductive antenna-emitter (LAE), boosted by an array of cylindrical sapphire-fiber-based microlenses, is reported. The observed enhancement is achieved, thanks to the sharp focusing of a pump laser beam near the semiconductor surface, for which the high-refractive-index sapphire lenses are used. We predict numerically and confirm experimentally a considerable enhancement in the emitted THz spectral power for such a sapphire-fiber-coupled LAE, as compared to an ordinary one with an equal electrode topology. In fact, a
≃
8.5-fold THz power boost is achieved, resulting in a +9.3 dB increase in the dynamic range. The results of our findings can be used to improve the performance of large-area THz devices, aimed at meeting the demands of rapidly developed THz spectroscopy, imaging, sensing, and exposure technologies.