30 Papers
211 Citations
Alex Quema is an academic researcher from National Institutes of Natural Sciences, Japan. The author has contributed to research in topics: Terahertz radiation & Magnetic field. The author has an hindex of 11, co-authored 30 publications.
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Papers
Teflon Photonic Crystal Fiber as Terahertz Waveguide
TL;DR: In this paper, the authors demonstrate the construction of reasonably long and non-polarization changing photonic fiber waveguide using Teflon which is a readily available and highly flexible material.
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Faraday ellipticity and Faraday rotation of a doped-silicon wafer studied by terahertz time-domain spectroscopy
Osamu Morikawa,Alex Quema,Shigeki Nashima,Hisashi Sumikura,Takeshi Nagashima,Masanori Hangyo +5 more
TL;DR: In this paper, the free-carrier Faraday ellipticity and Faraday rotation angles were measured for a moderately doped n-type silicon wafer with the resistivity of 1.1Ωcm under magnetic fields of ±3T using the terahertz time-domain spectroscopy.
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Excitation fluence dependence of terahertz radiation mechanism from femtosecond-laser-irradiated InAs under magnetic field
TL;DR: In this paper, the excitation fluence and magnetic field dependence of terahertz (THz) radiation power from InAs was investigated, and the results were explained by considering different THz-radiation mechanisms from the InAs surface with or without photoexcited carrier screening.
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Identification of Potential Estrogenic Environmental Pollutants by Terahertz Transmission Spectroscopy
Alex Quema,Hiroshi Takahashi,Masahiro Sakai,Masahiro Goto,Shingo Ono,Nobuhiko Sarukura,Ryu Shioda,Norihide Yamada +7 more
TL;DR: Using magnetically enhanced terahertz radiation from InAs, various naphthols, which exhibits estrogenic like activity and are potentially mimic natural hormones, are studied in this paper.
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Low-loss single-mode terahertz waveguiding using Cytop
Glenda De Los Reyes,Alex Quema,Carlito S. Ponseca,Romeric Pobre,R. Quiroga,Shingo Ono,Hidetoshi Murakami,Elmer Estacio,Nobuhiko Sarukura,Ko Aosaki,Yoshihiko Sakane,Hideki Sato +11 more
TL;DR: In this article, a planar planar photonic crystal waveguide (PPCW) was designed for guiding terahertz radiation, and it was shown that the propagation and coupling losses in the 0.2-1.1THz range are relatively small for a sheetlike thickness design.
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