CAVITY ENHANCED LASER BASED ISOTOPIC GAS ANALYZER

摘要

Systems and methods for measuring the isotope ratio of one or more trace gases and/or components of gas mixtures such as different gas species present in a gas mixture. The system includes a resonant optical cavity having two or more mirrors and containing a gas, the cavity having a free spectral range that equals the difference between frequencies of two measured absorption lines of different gas species in the gas, or of two different isotopes, divided onto an integer number. The system also includes a continuous-wave tunable laser optically coupled with the resonant optical cavity, and a detector system for measuring an absorption of laser light by the gas in the cavity. The detector system includes one of a photo-detector configured to measure an intensity of the intra-cavity light or both a photo-acoustic sensor configured to measure photo-acoustic waves generated in the cavity and a photo-detector configured to measure an intensity of the intra-cavity light.

主权项

1. A gas analyzer system for measuring a concentration of a component in a gas mixture, the system comprising:
a resonant optical cavity having two or more mirrors and containing a gas having a chemical species to be measured, wherein the cavity defines a plurality of cavity modes having a free spectral range (FSR), wherein an optical path length of the cavity is controlled or tuned so that a frequency of one of the plurality of cavity modes corresponds to an absorption frequency of the chemical species; a continuous-wave tunable laser optically coupled with the resonant optical cavity, wherein an output of the laser is scanned across a range of frequencies including the frequency of said one of the plurality of cavity modes; and a detector system for measuring an absorption of laser light by the gas in the cavity.