Patent ID: 9310294
Filing Date: 2016-04-12
CPC Classification: G01N,H01S

Claim Text:
1. A system for monitoring at least one gas in a sample gas, the system comprising: a source for generating a beam of radiation; at least one retro-reflector configured to receive the beam of radiation from the source in an incident direction and reflect the beam of radiation toward the source in alignment with the incident direction, thereby causing radiation in a cavity defined by the source and the at least one retro-reflector to obtain a desired wavelength; a motor configured to move the at least one retro-reflector with respect to the source in a direction collinear with the incident direction; a sample cell storing the sample gas comprising the at least one gas; a beam splitter located external to the cavity, the beam splitter configured to split the at least a portion of the extracted beam of radiation into at least (i) a first beam of radiation directed through the sample cell and (ii) a second beam of radiation directed through a reference path; a recombination device for interfering and recombining the first beam of radiation after traversing through the sample cell with the second beam of radiation to generate a first recombined beam of radiation; a detector in optical communication with the sample cell, wherein the detector is configured to generate a first recombined signal at the output of the sample cell based on the first recombined beam of radiation; and a processor, in electrical communication with the detector, configured to determine a concentration of the at least one gas in the sample gas based on a phase difference between the first recombined signal and a second recombined signal.