High sensitivity isotope concentration-ratio measurement CO/sub 2/ infrared laser system. II

摘要

For high sensitivity measurements of isotope concentration-ratios of trace-level gas mixture, particularly including carbon dioxide isotopes, we tested a /sup 12/CO/sub 2/-/sup 13/CO/sub 2/ composite laser system containing intracavity absorption cells. Sensitivity enhancement obtainable by the intracavity absorption cell configuration is examined theoretically. /sup 13/CO/sub 2/ in atmospheric air is readily detected and minimum detectable concentration by the present system was estimated to be 70 ppb.