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We achieved noise-free terahertz (THz)-wave output from an injection-seeded THz-wave parametric generator (is-TPG) employing high-power injection seeding. A conventional is-TPG uses a weak continuous-wave (CW) seed beam. The position in which broadband noise is generated (via spontaneous parametric down-conversion) and the position of the THz signal overlap. Thus, the output features broadband TPG noise, reducing the signal-to-noise ratio. To solve this problem, we shifted the position in which the THz signal is generated to the front of the crystal; we separated the signal from broadband TPG noise using a high-powered, pulsed seed beam that was 107-fold more powerful than the CW seed beam. Thus, we extracted only the THz signal; we achieved a noise-free is-TPG. This system features a signal-to-noise ratio of 95 dB, approximately 40 dB better than the signal-to-noise ratio of the conventional system.

In this study, we demonstrate real-time terahertz (THz) spectroscopy using a rapidly wavelength-switchable injection-seeded THz parametric generator. We developed a wavelength-switchable external cavity diode laser using a digital micromirror device as a seed source for the generator. We realized fast acquisition of THz spectra by switching the wavelength of the laser for each pump beam pulse. This system can rapidly switch wavelengths and easily increase the number of measurement wavelengths, and it also has a wide dynamic range, of more than 75 dB, and high stability. Furthermore, by combining this system with THz parametric detection, all wavelengths can be detected in a single frame using a near infrared camera for real-time reagent measurement.

形態: カラー図版あり, 会議情報: 第6回学際領域における分子イメージングフォーラム (2010年11月8日. 宇宙航空研究開発機構調布航空宇宙センター), 主催: 宇宙航空研究開発機構(JAXA)研究開発本部流体グループ・風洞技術開発センター, 形態: CD-ROM1枚, Original contains color illustrations, Meeting Information: 6th Interdisciplinary Forum on Molecular Imaging (November 8, 2010. Chofu Aerospace Center, Japan Aerospace Exploration Agency(JAXA)), Chofu, Tokyo Japan, Meeting sponsor: Fluid Dynamics Group and Wind Tunnel Technology Center, Aerospace Research and Development Directorate, Japan Aerospace Exploration Agency (JAXA), Note: One CD-ROM

We have developed a THz-wave spectrometer with the combination of a bright THz-wave source of THz-wave parametric generator (TPG) and a Martin- Puplett interferometer. The TPG output was optimized by studying various configurations with LiNbO3 crystals. THz-waves which span the 1-2THz region were emitted with the peak power of 280 micro W. The whole system, including the nitrogen-purge unit, was constructed in a table-top size. By use of the THz-wave spectrometer, absorption lines of water vapor were successfully obtained., Prepared in cooperation with GMM, VDE/VDE-Gesellschaft Mikroelektronik, Mikro- und Feinwerktechnik; ITS, Informationstechnische Gesellschaft im VDE; Photo Dynamics Research Center, RIKEN, Japan. This is from the THz Conference 2000 pp193-196. This article is from ADA398789 International Conference on Terahertz Electronics (8th), Held in Darmstadt, Germany on 28-29 September 2000