摘要 |
<p>A method and apparatus for detecting the presence of a specific concentration of gaseous species within a calibrated range in a gas sample is disclosed. The ILS gas detection system (10) of the present invention simply comprises an ILS laser (12), a wavelength-selective optical element (52), and an optical detector (16). However, the potential or operational wavelength bandwidth of the ILS laser (12) is preferably entirely included within one of the absorption bands or regions assigned to the intracavity gaseous species being monitored. Thus, within the calibrated range, the presence of the gaseous species changes the output laser wavelength or output intensity at the specific wavelength of the ILS laser (12). Consequently, only the wavelength of the output or the output intensity at the specific wavelength of the ILS laser (12) need be monitored in order to quantitatively determine the concentration of the absorbing gaseous species within a calibrated range when using the ILS method of the present invention.</p> |