Frequency resolution and accuracy improvement of a GaP CW THz spectrometer

Tetsuo Sasaki, Tadao Tanabe, Jun Ichi Nishizawa

Research output: Chapter in Book/Report/Conference proceedingConference contribution


High resolution terahertz (THz) spectroscopy is available for sensitive gas detection and also useful for vibrational mode analysis of organic molecules. We developed a widely frequency tunable (0.1-7.5 THz), monochromatic coherent THz-wave Signal Generator on the basis of difference frequency generation (DFG) in a GaP crystal via excitation of phonon-polariton mode under small-angle non-collinear phase matching condition. The pump beams for DFG were supplied from semiconductor lasers as seed beams after amplification by fiber amplifiers. Then we applied it as a light source for a high resolution and high accuracy THz spectrometer. Combining with a superconducting Transition Edge Sensor (TES) bolometer cooled by a pulse tube refrigerator, a non-stop spectrometer system was realized. The system had advantages of high stability, small size, easy operation and maintenance free in the lifetime of the pump lasers. As frequency resolution and accuracy were limited by those of pump laser beams, we have newly developed a frequency control system for two beams at the same time. Frequency resolution of 8 MHz constant in whole the frequency tunable range and absolute accuracy of better than 3 MHz were evaluated by the measurements of water vapor absorptions in vacuum.

Original languageEnglish
Title of host publicationRecent Global Research and Education
Subtitle of host publicationTechnological Challenges - Proceedings of the 15th International Conference on Global Research and Education Inter-Academia 2016
EditorsRyszard Jabłoński, Roman Szewczyk
PublisherSpringer Verlag
Number of pages6
ISBN (Print)9783319464893
Publication statusPublished - 2017
Externally publishedYes
Event15th International Conference on Global Research and Education, INTER-ACADEMIA 2016 - Warsaw, Poland
Duration: 2016 Sept 262016 Sept 28

Publication series

NameAdvances in Intelligent Systems and Computing
ISSN (Print)2194-5357


Conference15th International Conference on Global Research and Education, INTER-ACADEMIA 2016

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Computer Science(all)


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