Time division multiplexed gas sensing system with a forward-coupled ladder topology

H. L. Ho, W. Jin, M. S. Demokan

Research output: Journal article publicationConference articleAcademic researchpeer-review


Quantitative measurement of gas concentration based on wavelength modulation spectroscopy (WMS) and second-harmonic detection is demonstrated by applying low-frequency wavelength modulation to an external-cavity tunable diode laser. The tunable laser operating at 1.53 μm region is used to detect acetylene (C2H2) with laser absorption spectroscopy. A time-division multiplexed three-sensor system with a forward-coupled ladder topology have been implemented and experimentally tested. The sensor system uses single path 25 mm absorption cells and have demonstrated sensitivity of 81 ppm. The crosstalk between the sensors was found to be -30 dB. Power budget analysis shows that a sensor network consisting of 37 sensors could be realized with the same multiplexing topology.

Original languageEnglish
Pages (from-to)7-10
Number of pages4
JournalProceedings of SPIE - The International Society for Optical Engineering
Publication statusPublished - Jun 2000
EventInternational Conference on Sensors and Control Techniques (ICSC 2000) - Wuhan, China
Duration: 19 Jun 200021 Jun 2000

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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