PCF-based cavity enhanced spectroscopic sensors for simultaneous multicomponent trace gas analysis

Sensors (Basel). 2011;11(2):1620-40. doi: 10.3390/s110201620. Epub 2011 Jan 27.


A multiwavelength, multicomponent CRDS gas sensor operating on the basis of a compact photonic crystal fibre supercontinuum light source has been constructed. It features a simple design encompassing one radiation source, one cavity and one detection unit (a spectrograph with a fitted ICCD camera) that are common for all wavelengths. Multicomponent detection capability of the device is demonstrated by simultaneous measurements of the absorption spectra of molecular oxygen (spin-forbidden b-X branch) and water vapor (polyads 4v, 4v + δ) in ambient atmospheric air. Issues related to multimodal cavity excitation, as well as to obtaining the best signal-to-noise ratio are discussed together with methods for their practical resolution based on operating the cavity in a "quasi continuum" mode and setting long camera gate widths, respectively. A comprehensive review of multiwavelength CRDS techniques is also given.

Keywords: 07.57.Ty; 07.60.Rd; 07.88.+y; 33.20.Kf; 37.30.+i; 42.55.Tv; 42.79.Gn; PACS 07.07.Df; cavity ring-down absorption spectroscopy; cavity-enhanced absorption spectroscopy; molecular spectroscopy; photonic crystal fibres; supercontinuum lasers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorption
  • Crystallization
  • Gases / analysis*
  • Optical Phenomena
  • Optics and Photonics / instrumentation*
  • Spectrum Analysis / instrumentation*
  • Water / chemistry


  • Gases
  • Water