Gas detection with evanescent-wave quartz-enhanced photoacoustic spectroscopy

Yingchun Cao, Wei Jin, Hoi Lut Ho

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

4 Citations (Scopus)


Evanescent-wave gas sensing with tapered optical fibers (TOFs) and quartz-enhanced photoacoustic spectroscopy (QEPAS) is reported. The evanescent field of TOFs with diameter down to sub-wavelength is utilized for photoacoustic excitation in photoacoustic spectroscopy. A quartz tuning fork (QTF) with resonant frequency about ~32.75 kHz is used to detect the generated pressure wave. A normalized noise equivalent absorption coefficient of 1.5×10-6cm-1W/√Hz is achieved for acetylene detection with a fiber taper with a waist diameter of 1.1 μm. It is found that QEPAS with TOFs of sub-wavelength diameters exhibit comparable sensitivities with open path QEPAS but with additional advantages of lower insertion loss, easier alignment, and multiplexing capability.
Original languageEnglish
Title of host publicationThird Asia Pacific Optical Sensors Conference
Publication statusPublished - 20 Feb 2012
Event3rd Asia Pacific Optical Sensors Conference - Sydney, NSW, Australia
Duration: 31 Jan 20123 Feb 2012


Conference3rd Asia Pacific Optical Sensors Conference
CitySydney, NSW


  • evanescent field
  • gas sensor
  • Optical fiber sensor
  • photoacoustic spectroscopy
  • tapered optical fiber

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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