NIR diode laser-based QEPAS for acetylene detection

Yingchun Cao, Wei Jin, Hoi Lut Ho

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

1 Citation (Scopus)

Abstract

Quartz-enhanced photoacoustic spectroscopy with a near infrared distributed feedback diode laser at 1.53 μm is demonstrated for acetylene detection at atmospheric pressure and room temperature. The P(9) absorption line in the ν 1+ν 3 band of C 2H 2 is selected for light absorption and photoacoustic pressure wave excitation. A pair of resonant tubes with optimal dimensions is used in combination with a quartz tuning fork for photoacoustic signal enhancement. The wavelength of diode laser is modulated at half of the resonant frequency of tuning fork for second harmonic signal detection. The effect of residual amplitude modulation is theoretically analyzed and compared with the experimental results. A noise-limited minimum detectable concentration (1σ) of 2 part-per-million (ppm) is achieved with a 7-mW laser power and a 1-s lock-in time constant, corresponding to a normalized noise equivalent absorption coefficient of 5.4×10 -8 cm -1 W/√Hz.
Original languageEnglish
Title of host publicationOptical Sensing and Detection II
Volume8439
DOIs
Publication statusPublished - 12 Jun 2012
EventOptical Sensing and Detection II - Brussels, Belgium
Duration: 16 Apr 201219 Apr 2012

Conference

ConferenceOptical Sensing and Detection II
Country/TerritoryBelgium
CityBrussels
Period16/04/1219/04/12

Keywords

  • Acetylene detection
  • QEPAS
  • Quartz tuning fork
  • Residual amplitude modulation
  • Wavelength modulation

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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