講演情報
[10p-E203-1]Terahertz imaging and dichroism detection using carbon nanotube fiber p-n Junctions.
〇(P)Miguel Angel Lopez1, Satoshi Kusaba1,2, Koki Shiba1, Shigeki Saito1, Ryo Tamaki2,3, Atsushi Yamaguchi4, Yoshihiro Yokoi4, Tsukasa Matsuura4, Junichiro Kono5, Jun Takeda2,6, Ikufumi Nakayama2, Kazuhiro Yanagi1 (1.Tokyo Metropolitan U, 2.Yokohama Nat. U., 3.Keio U., 4.Tokai Rika Co. Ltd., 5.Rice U., 6.Shibaura Inst. Tech.)
キーワード：
Carbon Nanotube、Terahertz、Fiber
Detection of terahertz (THz) circular polarization is a significant key technology for various applications including THz circular dichroism spectroscopy to detect chirality for molecules, crystals, and structures smaller than the diffraction limit. However, developing simple and controllable THz polarization detectors has been in progress in past few decades [1]. Here, we demonstrate circularly polarized terahertz detection based on a carbon nanotube (CNT) fiber p-n junction detectors, which are fabricated by interlacing and twisting a p- and a n-doped CNT fibers. This simple structure generates a photothermoelectric (PTE) voltage under THz irradiation. We built a 2D scanning system using a CNT fiber p-n junction as a THz detector and an impact ionization avalanche transit time (IMPATT) diode as a THz emitter.
Furthermore, we have found that twisting fiber induces circular polarization selection rules depending on the helicity of the twisted fibers [2]. The dissymmetry factors (g~1) of our twisted fiber representing the magnitude of circular dichroism indicate a good differentiation between left- and right-handed polarization, this opens the possibility for a direct THz dichroism detection by combining left- and right-handed twisted p-n junctions. By controlling the twist of the CNT fiber p-n junction, the 2D scanning system can distinguish the handedness of simple metasurface structures. Our results open a new “textile engineering” THz device fabrication strategy for fabrication of 1D and 2D THz devices through different interlacing and twists of p-and n-type CNT fibers.
[1] M. Asada et al., Sensors, 21, 4 (2021).
[2] K. Shiba et al., The 69th Fullerenes-Nanotubes-Graphene General Symposium 1P-46 (2025).
This study is supported by NEDO, JST, and JSPS.
Furthermore, we have found that twisting fiber induces circular polarization selection rules depending on the helicity of the twisted fibers [2]. The dissymmetry factors (g~1) of our twisted fiber representing the magnitude of circular dichroism indicate a good differentiation between left- and right-handed polarization, this opens the possibility for a direct THz dichroism detection by combining left- and right-handed twisted p-n junctions. By controlling the twist of the CNT fiber p-n junction, the 2D scanning system can distinguish the handedness of simple metasurface structures. Our results open a new “textile engineering” THz device fabrication strategy for fabrication of 1D and 2D THz devices through different interlacing and twists of p-and n-type CNT fibers.
[1] M. Asada et al., Sensors, 21, 4 (2021).
[2] K. Shiba et al., The 69th Fullerenes-Nanotubes-Graphene General Symposium 1P-46 (2025).
This study is supported by NEDO, JST, and JSPS.