title: Measurement of (12)CO(2):(13)CO(2) ratios for medical diagnostics with 1.6-µm distributed-feedback semiconductor diode lasers.
abstract: We have observed some of the absorption lines from the molecules (12)CO(2) and (13)CO(2)in the 1.6-µm spectral region with the use of specially fabricated single-mode InGaAsP distributed-feedback semiconductor diode lasers. Using a 23.6-m-long multipass absorption cell in combination with radio-frequency modulation and detection techniques, we measured the (12)CO(2):(13)CO(2) isotopic ratio of two specific lines at 6253.73 and 6253.90 cm(-1) with sufficient precision for diagnostic medical tests that analyze CO(2) on human breath.
authors.forename: D E
authors.initials: DE
authors.lastname: Cooper
authors.forename: R U
authors.initials: RU
authors.lastname: Martinelli
authors.forename: C B
authors.initials: CB
authors.lastname: Carlisle
authors.forename: H
authors.initials: H
authors.lastname: Riris
authors.forename: D B
authors.initials: DB
authors.lastname: Bour
authors.forename: R J
authors.initials: RJ
authors.lastname: Menna