| 摘要 |
A cavity ring down gas sensor is disclosed. In one illustrative embodiment, the cavity ring down gas sensor includes an electromagnetic radiation source (e.g. laser) configured to emit an input beam of light having a wavelength corresponding to an absorption line of a gas to be detected. The input beam of light may be coupled into an optical cavity to amplify an internal beam of light that is reflected about the optical cavity. An optical element may be disposed in the optical cavity at an angled close to, but not at, the Brewster's angle to reflect a relatively small portion of the internal beam of light in the optical cavity to a detector for determining the intensity of the internal beam of light in the optical cavity. When a specified light intensity is reached in the optical cavity, the input beam of light may be shut off or otherwise prevented from entering the optical cavity, and a cavity ring down time decay may be measured. The cavity ring down time decay may be related to the gas concentration of a gas to be detected in the optical cavity. |
