論文

2019年9月

Terahertz differential absorption spectroscopy using multifurcated subnanosecond microchip laser

APPLIED PHYSICS LETTERS
  • Yuma Takida
  • ,
  • Toshiyuki Ikeo
  • ,
  • Kouji Nawata
  • ,
  • Yoshio Wade
  • ,
  • Yasuhiro Higashi
  • ,
  • Hiroaki Minamide

115
12
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1063/1.5119411
出版者・発行元
AMER INST PHYSICS

Using spectral multifurcated oscillations in a passively Q-switched microchip laser, we demonstrate frequency-domain differential absorption spectroscopy in the terahertz (THz) frequency region. Within a single quasi-continuous-wave (QCW) excitation, a microchip laser comprising a 7-mm-long Nd:YAG/Cr:YAG composite ceramic provides up to three subnanosecond pulses with a 1064-nm wavelength and a 50-Hz QCW repetition rate. We have observed that the longitudinal mode of double and triple pulses shows stable bifurcation and trifurcation, respectively, induced by a spatial hole burning effect within the laser cavity. These pulses are directly used to drive an injection-seeded THz-wave parametric generator based on a MgO-doped LiNbO3 crystal, thereby generating up to three monochromatic, self-frequency-switched THz-wave pulses separated from each other in frequency by a free spectral range of the laser cavity. By precisely tuning one of the THz-wave frequencies to the gas absorption line, multifurcated THz-wave pulses facilitate the measurement of differential absorption signals every 20 ms without any active frequency modulation. We also show that first- and second-order derivative spectra of gas absorption can be derived from a single frequency sweep of multifurcated pulses without a reference spectrum and computational derivation. Our approach paves the way toward realization of a THz differential absorption lidar for use in fast gas sensing applications.

リンク情報
DOI
https://doi.org/10.1063/1.5119411
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000487038900005&DestApp=WOS_CPL
ID情報
  • DOI : 10.1063/1.5119411
  • ISSN : 0003-6951
  • eISSN : 1077-3118
  • Web of Science ID : WOS:000487038900005

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